WO2013124769A1

WO2013124769A1 - Method of monitoring and controlling rodents with heat-treated wood

Info

Publication number: WO2013124769A1
Application number: PCT/IB2013/051208
Authority: WO
Inventors: James H. Cink
Original assignee: Basf Se
Priority date: 2012-02-23
Filing date: 2013-02-14
Publication date: 2013-08-29

Abstract

A rodent attractant for use in monitoring and controlling rodents includes a heat-treated wood. Heat-treated wood is wood that has been heat treated to a temperature of greater than about 150 degrees C. A method of monitoring rodents includes locating the heat-treated wood in an area accessible to rodents and monitoring the heat-treated wood for the presence of rodents. A method of controlling rodents includes locating the heat-treated wood and a rodenticide in an area accessible to rodents.

Description

METHOD OF MONITORING AND CONTROLLING

RODENTS WITH HEAT-TREATED WOOD

BACKGROUND

[0001] Drying wood is known in the field of wood preparation and preservation. There is a broad spectrum of processes that are utilized to dry wood. One such process occurs naturally to wood maintained at atmospheric conditions, such as with the aging of cut logs on a wood pile. This drying reduces the water content of the wood, while the wood remains susceptible to decay and cellular degeneration due to fungal pathogens, for example. Other drying techniques utilize heated chambers, such as kilns, maintained at elevated temperatures, such as those between about 40 degrees C ( 105 degrees F) and about 90 degrees C (195 degrees F), to more quickly dry wood. Wood dried in this manner is conventionally utilized as lumber, such as for construction projects and the like. Other conventional drying processes utilize high-temperature steam to dry wood at temperatures of between about 90 degrees C (195 degrees F) and about 150 degrees C (302 degrees F). This temperature level provides shorter drying times and more dimensionally-stable lumber, as compared with the previously discussed processes. Such conventional lumber is typically marketed for sale having a water c ontent of between about 15 percent and about 18 percent. Once such lumber is in use in an ambient environment for some time, such as in a frame house, the wood has a water content of between about 10 percent and about 15 percent.

[0002] Another conventional wood drying process utilizes even more elevated

temperatures, such as between about 150 degrees C (302 degrees F) and about 215 degrees C (420 degrees F) to alter the color of the wood itself. The upper limit on the heating can be higher than the 215 degrees C (420 degrees F) noted above, as long as the temperature remains below the charring temperature of the treated wood. Such processing is conventionally utilized to create the appearance of stained wood, without the use of chemical stains. Because such wood is superheated to elevated temperatures, much of the water content is removed from the wood, bringing water levels in the heat-treated wood to between about 2 percent and about 10 percent. Although this process is known in the art of wood preparation and preservation, the wood product created by the process has not been used conventionally as a medium for monitoring or controlling rodents. SUMMARY

[0003] In one aspect, a method of monitoring rodents generally comprises locating a wood that has been heat-treated to a temperature of greater than about 150 degrees C in an area accessible to rodents and monitoring the heat-treated wood for the presence of rodents.

[0004] In another aspect, a method of controlling rodents generally comprises locating a wood that has been heat-treated to a temperature of at least about 150 degrees C in an area accessible to rodents and locating a rodenticide in the area.

[0005] In yet another aspect, a method of controlling rodents generally comprises locating a toxic bait comprising wood that has been heat-treated to a temperature of at least about 150 degrees C and a rodenticide within an area accessible to rodents.

[0006] In still another aspect, a method of controlling rodents generally comprises locating a rodent management station in an area accessible to rodents. The rodent management station comprises a housing and at least one opening therein providing communication between an interior and the exterior of the housing. A trap is positioned within the interior of the housing. A heat-treated wood is placed in the interior of the housing. The heat-treated wood comprises wood that has been heat-treated to a temperature of greater than about 150 degrees C.

[0007] In a further aspect, a rodent attractant for use in monitoring and controlling rodents generally comprises a heat-treated wood. The heat-treated wood comprises a wood that has been heat treated to a temperature of greater than about 150 degrees C.

[0008] In still a further aspect, a rodent trap assembly comprises a trap and a heat-treated wood for attracting rodents to the trap. The heat-treated wood comprises wood that has been heat-treated to a temperature of greater than about 150 degrees C.

[0009] In another aspect, a toxic rodent bait generally comprises a heat-treated wood and a rodenticide. The heat-treated wood comprises a wood that has been heat treated to a temperature of greater than about 150 degrees C.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Fig. 1 is a perspective view of one embodiment of a rodent management station in a closed configuration;

[001 1] Fig. 2 is a perspective view of the rodent management station of Fig. 1 in an open configuration; [0012] Fig. 3 is a perspective view of the rodent management station in the open configuration and with bait positioned horizontally in the station;

[0013] Fig. 4 is a perspective view similar to Fig. 3 but with bait positioned vertically in the station;

[0014] Fig. 5 is a top plan view of the rodent management station with a snap trap positioned therein; and

[0015] Fig. 6 is a perspective view of the rodent management station in the open configuration and with a live trap and bait positioned in the station.

DETAILED DESCRIPTION

[0016] Referring now to the drawings and in particular to Figs.1 and 2, one embodiment of a rodent management system generally comprises a rodent management station, which is indicated generally at 100, and includes a housing having an interior space and at least one and more suitably two entry openings 102 formed therein through which rodents enter the interior space of the station. In accordance with one suitable embodiment, the entry openings 102 are suitably sized and configured to facilitate a feeling of comfort to rodents that approach and partially enter the station 100 housing to entice the rodent to further enter the station. Each entry opening 102 of the illustrated embodiment has a generally one-quarter circle shape or one- quarter circle ellipse. The illustrated rodent management station 100 is of a modular design, permitting a plurality of selective bait and/or trap configurations as will be described in further detail later herein.

[0017] As seen in Figs. 1 and 2, the rodent management station 100 comprises a base, indicated generally at 104, and a lid, indicated generally at 106, (together broadly defining the station housing) that is releasably connectable to the base for positioning relative to the base between an opened configuration and a closed configuration of the station. In the closed configuration (Fig. 1), the lid 106 and base 104 together form a substantially enclosed interior space, with the entry openings 102 disposed in opposite sides of the station 100, and more particularly in opposite sides of the lid 106.

[0018] In the opened configuration (Fig. 2), the lid 106 is generally positioned at least in part away from the base to provide access to the interior space of the rodent management station 100 for maintenance of the station such as, without limitation, replenishing bait supply, inspecting the rodent management station 100, placing and/or resetting traps, and clearing debris from the rodent management station 100. The base 104 and lid 106 may be suitably fabricated from any number of materials, most suitably plastic or other weather resistant material. For example, the base 104 and lid 106 may be formed in an injection molding process used for producing parts from thermoplastic or thermosetting plastic materials. It is understood, however, that the base 104 and lid 106 may be constructed of metal or other suitable materials, and that the base and the lid may be constructed of different materials from each other, without departing from the scope of this invention.

[0019] The lid 106 is suitably hinged to the base 104, such as by a living hinge 108 (or a plurality of living hinges) in which a continuous piece of material formed integrally with the lid and base (as in the illustrated embodiments) defines the hinge, a mechanical hinge or other suitable hinge configuration to permit hinged movement of the lid between the opened and closed configurations of the station while maintaining connection of the lid with the base to inhibit loss of the lid during servicing of the rodent management station 100. It is understood that the lid 106 may be attached to the base 104 other than by a hinge and remain within the scope of this invention. It also contemplated that the lid 106 may be entirely separable from the base 104 without departing from the scope of this invention. In the closed configuration of the station 100, the lid 106 and base 104 are further releasably held together by a suitable locking mechanism, indicated generally at 142, to inhibit unauthorized or unintended opening of the rodent management station 100.

[0020] As seen in Fig. 1, the illustrated lid 106 suitably comprises laterally opposite side walls 110 that broadly define opposite sides of the rodent management station 100, a front wall 136 broadly defining a front of the rodent management station and a top wall 137 broadly defining a top of the rodent management station. In the illustrated embodiment the side walls 110, the top wall 137 and the front wall 136 of the lid 106 together define a generally quarter- dome shape although the top wall 137 is slightly flattened as it approaches the base 104. It is understood, however, that the lid 106 may be shaped other than as illustrated without departing from the scope of this invention, and that in alternative embodiments the base may instead, or additionally define one or more the sides of the rodent management station and/or the front of the station.

[0021] As illustrated in Fig. 2, the lid 106 further comprises interior panels 1 12 (broadly, partition structure) depending therefrom to partition the enclosed interior space of the rodent management station 100 into a suitable layout for rodent management. These interior panels 1 12 may be molded together with other lid components (e.g., the top wall 137, side walls 1 10, and/or front wall 136) or formed separate therefrom and connected thereto by adhesive, welding, fastening or other suitable attachment technique.

[0022] The base 104 comprises a floor panel, or bottom panel 1 14, which defines a bottom of the housing and more particularly of the rodent management station 100, and an inner surface or floor on which rodents move within the interior space of the station. The base 104 also has an upstanding wall 116 (otherwise referred to herein as an upstanding sidewall or rear wall) extending upward relative to the bottom panel 1 14 about substantially less than the entire circumference of the bottom panel. Such an arrangement permits (with all internal traps removed from the housing) debris to be easily swept off of the floor of the housing when the lid 106 is opened for servicing, e.g., without having to reach into the station and remove debris or tilt or turn over the base 104 of the rodent management station. For example, the

circumferential extent of the upstanding wall 1 16 according to one embodiment is such that a continuous circumferential segment of at least about 25 percent of the bottom panel 1 14 is free from enclosure by the at least one upstanding wall. In the illustrated embodiment of Fig. 2, the at least one upstanding wall comprises an upstanding rear wall 116 of the base (thereby also defining a rear of the housing and more particularly of the rodent management station 100) extending solely along the rear extent of the floor panel 114.

[0023] In one suitable embodiment, an inner surface 1 18 of the bottom panel 1 14 (e.g., the floor of the housing) tapers, or slopes downward from a central region of the inner surface toward at least the laterally opposite sides of the housing (e.g., where the side walls of the lid generally abut the bottom panel). In the illustrated embodiment, the inner surface 118 of the bottom panel 114 remains relatively planar as is extends from the central region thereof to the front of the station 100. However, it is also contemplated that additionally, or instead, at least a portion of the inner surface 1 18 of the bottom panel 1 14 may taper or slope downward from the central region thereof toward the front of the housing (e.g., where the front wall of the lid abuts or is hinged to the bottom panel). Providing such a slope or taper to the inner surface 118 of the bottom panel 1 14 facilitates water drainage off of the bottom panel and out of the rodent management station 100 should water enter the interior space of the housing.

[0024] The rear wall 116 of the base 104 includes an inner panel 117 or surface having elongate, vertically extending slots 132 formed therein. The slots 132 are spaced laterally apart from each other along the inner surface of the rear wall 1 16, and may be of uniform length but more sui tably are of varying lengths wi th some slots 132 being l onger th an others. Each of the slots 132 is open at the top of the rear wall 116 and extends down to a location generally intermediate the top and bottom of the rear wall (for the shorter slots) or to adjacent the bottom of the rear wall (e.g., just above the inner surface of the bottom panel, for the longer slots).

[0025] As seen in Fig. 2, the interior panels 112 (i.e., the internal partition structure) depending from the lid 106 are suitably configured to depend into abutting or closely spaced relationship with the inner surface 1 18 of the bottom panel 1 14 of the base 104 when the lid is closed. These interior panels 1 12 thus provide additional crush resistance to the lid, such as upon a downward force being applied to the lid. The interior panels 1 12 also partition the interior space of the housing into a generally central bait chamber 138 (e.g., above the central region of the inner surface 1 18 of the bottom panel 1 14) and a pair of generally curved pathways 103 that are defined at least in part by the interior panels. These pathways 103 each extend away from the respective entry opening 102 and lead to the bait chamber 138. An entryway to the bait chamber 138 is also defined at least in part by the interior panels 1 12. More particularly, in the illustrated embodiment the pathways 103 are defined by the interior panels 1 12 and by the lid 106. The pathways 103 together form a single open passageway that extends from one entry opening 102, around to adjacent the front of the station 100, past the entryway to the bait chamber 138 and back around to the opposite entry opening. The tortuous passageway prevents rodents entering the rodent management station 100 at the entry openings 102 from traveling straight through the rodent management station 100 from one entry opening to the other.

[0026] The central bait chamber 138 is suitably defined in part by the interior panels 112 and in part by the inner panel 117 of the rear wall 116. A suitable trap mechanism and/or bait may be positioned within the central bait chamber 138, with the interior panels 1 12 restricting access to the bait chamber, i.e., by omitting direct access to the bait chamber from the entry openings 102 in the rodent management station. Thus, non-targeted animals (e.g., dogs or cats) and unauthorized individuals (e.g., children) cannot easily reach through the entry openings 102 into the bait chamber when the lid is closed.

[0027] Upon entering the rodent management station 100 through one of the openings 102 and traveling along the passageway, the rodent is able to enter the bait chamber 138 via the entryway defined by the interior panels 112. In one particularly suitable embodiment, the height of the bait chamber 138 (e.g., the vertical distance from the inner surface of the bottom panel 114 of the base 104 to the inner surface of the top wall 137 of the lid 106) is sufficient to permit the rodent to ingest bait while in a generally upright, seated position as is typically preferred by- rodents. For example, while the height of the bait chamber 138 in one embodiment may be non- uniform due to the taper of the lid 106, the bait chamber 138 suitably has a maximum height of about 5.7 inches.

[0028] With particular reference now to Figs. 3 and 4, bait, such as bait blocks 156, can be disposed within the bait chamber 138 and more suitably toward the back of the bait chamber generally adjacent the rear wall of the base 104. Many different types of bait are available, and their general compositions and principles of operation are well known in the art. Such baits may solely comprise a rodent attractant and others may additionally, or alternatively, comprise one or more toxins intended to kill the rodents.

[0029] Suitable bait supports 158 are used within the rodent management station 100 for positioning and retaining the bait within the bait chamber 138, and more suitably for supporting such bait in spaced relationship above the floor of the housing (e.g., above the inner surface 118 of the bottom panel 114). In the embodiment of Fig. 3, a plurality of bait blocks 156 are mounted on a "skewer" 160, or wire support which in turn is supported by the bait supports 158 in a horizontal orientation. The skewer 160 passes through a hole in each of the bait blocks 156 - the hole being centrally located in the bait block although the hole need not be centrally located. In the embodiment of Fig. 4, the bait blocks 156 are stacked vertically in one or more columns when supported by the bait supports 158. It is also understood that the bait may be other than in the shape of a block or cube without departing from the scope of this invention.

[0030] With particular reference now to Fig. 5, the rodent management station 100 is suitably modular to permit a snap trap 170 (e.g., a conventional mouse trap) to be placed in the bait chamber 138. The illustrated snap trap 170, for example, is similar in design to one commercially available from Kness Manufacturing Company, Inc. of Albia, Iowa. While an exemplary snap trap 170 is depicted in Fig. 5, it understood that other suitable traps may be used within the scope of this invention.

[0031] In such a configuration of the rodent management station 100, the bait blocks 156 may be supported on the rear wall of the base 104 as described previously in combination with the snap trap 170. Thus, the bait blocks 156 illustrated in Figs. 3 and 4 can be used with snap trap 170. In another configuration, the snap trap 170 may be baited in a manner known in the art instead of or in addition to the bait blocks 156.

[0032] In one particularly suitable embodiment, the snap trap 170 is disposed and oriented in the bait chamber 138 with a portion of the trigger mechanism of the snap trap extending through the bait chamber entryway into the passageway outside the bait chamber (as seen in Fig. 5). In this manner, bait may be placed on the trap 170 (or on the rear wall 116 as in the previous embodiments) to allow the rodent to smell and in some instances see the bait. As the rodent continues along the passageway in search of the bait, the rodent must cross over the trigger mechanism of the snap trap. In particular-, the rodent is prevented from continued travel along the passageway to the opposite entry opening 102 without crossing over the trigger mechanism of the snap trap 170.

[0033] With reference still to Fig. 5, a horizontal frame 172 (broadly, a "trap placement member") such as a wire frame or other suitable frame construction can be provided to retain the snap trap 170 against sliding or other movement of the trap within the rodent management station 100. In other embodiments, the snap trap 170 may be affixed or reieasably secured to the frame 172 by suitable fasteners or adhesives. In still other embodiments, the base of the snap trap may have a recess formed into its perimeter. The frame 172 in such an embodiment may then rest in the recess to retain the snap trap in position within the rodent management station.

[0034] The modular configurability of the rodent management station 100 further allows what is commonly referred to as a "live trap" to be placed in the rodent management station instead of (e.g., interchangeably with, although it is contemplated that it may be in addition to) the snap trap 170 of Fig. 5. Live traps are traps designed to trap a rodent, typically a mouse, within an enclosure without having to poison or immediately kill the rodent. One suitable embodiment of a live trap configured for use within the rodent management station 100 is illustrated in Fig. 6 and generally indicated at 200. It is understood, however, that other live trap configurations may be used within the rodent management station 100.

[0035] In the illustrated embodiment, the live trap 200 is located and held in place within the rodent management station by stabilizing members 204 disposed on and more suitably formed integrally with the exterior of the live trap 200. These stabilizing members 204 abut against the interior panels 1 12 depending from the lid 106 when the lid is closed to provide stability and support to the live trap 200 against movement within the housing. The contact between the stabilizing members 204 and the interior panels 1 12 also increases the structural rigidity of the lid 106 and in particular of the interior panels.

[0036] As illustrated in Fig. 6, bait such as the bait blocks 156 may be disposed within the bait chamber 138 along with the live trap 200, such as above the chamber portion of the live trap. The bait blocks 156 serve to lure the rodent into the rodent management station and toward the live trap and/or bait chamber 138. In such an embodiment, the live trap 200 may be sized to allow only smaller rodents such as mice to enter the live trap. Larger rodents such as rats will climb over the top of the live trap 200 into the bait chamber 138 and feed on the bait which may be sufficiently toxic to kill the rat. Additionally, non-toxic baits (e.g., monitoring baits) may be used in the rodent management station 100. Monitoring bait is a non-toxic substance that indicates the presence of rodents by virtue of it being consumed by rodents over a period of time.

[0037] In one suitable embodiment, the bait blocks 156 comprise heat-treated wood. It has been found in laboratory testing, which is discussed below, that heat-treated wood can be used to attract or lure rodents (especially female rodents) into the rodent management system 100 and more specifically, into the bait chamber 138 of the rodent management system. It is understood that the heat-treated wood could be in other forms besides bait blocks (e.g., pieces, chips, pellets, shavings, particles, powder). It is also understood that the heat-treated wood can be used in addition to the bait blocks 156. For example, the heat-treated wood can be used as an attractant and the bait blocks 156 can be used monitoring and/or toxic bait. It is understood, however, that in addition to being used as an attractant heat-treated wood can be used as a monitoring and/ or toxic bait. In one suitable embodiment, for example, the bait blocks 156 can comprise heat-treated wood impregnated (or otherwise treated) with a rodent toxin (i.e., a rodenticide).

[0038] It is contemplated that in other suitable embodiments, the heat-treated wood can be used independent of the rodent management station 100 or with other types of rodent management stations. For example, the heat-treated wood can be used with a snap trap (e.g., the snap trap 170 illustrated in Fig. 5), a live trap (e.g., the live trap 200 illustrated in Fig. 6) or other conventional rodent traps (e.g., glue board, electric traps) to attract or lure rodents to the trap.

[0039] In one particularly suitable embodiment, the heat-treated wood comprises a wood that has been heat treated at an elevated temperature, such as at least about 150 degrees C (302 degrees F) and more suitably between about 150 degrees C and 215 degrees C (420 degrees F). Wood is an organic material found as the primary content of the stems of woody plants (e.g., trees and shrubs). Dry wood is composed of fibers of cellulose (from about 40 percent to about 50 percent by dry weight) and hemicelluloses (from about 20 percent to about 30 percent by dry weight) held together by lignin (from about 25 percent to about 30 percent by dry weight). Wood also contains extractives, which are compounds that can be extracted using various solvents and are often less than 500 grams/mole in molecular weight. In general, these extractives constitute from about two percent to about eight percent (dry weight) of the wood components.

[0040] Cellulose is the most abundant component in wood and plays a major role in giving wood its mechanical strength. A molecule of cellulose consists of β-D-glucose units bonded with β(1→ 4) lingages to form a long linear chain and has a molecular weight that ranges from several thousand to many million grams/mole. The molecular chains in cellulose form elementary fibrils or micelles. The micelles align with the cellulose fibrils oriented in the same direction and are tightly packed together. Cellulose elementary fibrils are then layered together in parallel with hemicelluloses and pectins in between to form microfibrils. When the microfibrils are aggregated in larger bundles and lignin impregnated within the structure, fibrils are generated, which in turn form wood fibers.

[0041] Hemicelluloses comprise from about 20 percent to about 30 percent by dry weight. Smaller than cellulose molecules, the average molecular weight of hemicelluloses range from about 10,000 grams/mole to about 30,000 grams/mole. The composition of hemicelluloses varies between hardwoods (i.e., oak, mahogany) and softwoods (i.e., pine, cedar). The hemicelluloses of hardwoods are predominantly of glucuronoxylan (from about fifteen percent to about 30 percent) and to a minor extent glucomannan (from about two percent to about five percent). The hemicelluloses of softwoods consist predominantly of gaiactogiucomannan (about twenty percent) and smaller amounts of arabinoglucuroxylan (from about five percent to about ten percent).

[0042] Pectins and starch are also found in wood, but typically in minor amounts, less than about one percent each. Pectins resemble hemicelluloses in structure and are found in the middle lamella, primary cell wall and tori of bordered pits and also to a small extent in the fibril structure. Starch can be found in parenchyma cells serving as storage of nutrition for the living tree, and it consists of amylase and amylopectin.

[0043] Lignin is an amorphous polymer with a wide variation in configuration. Lignin is often considered to be the glue of the wood structure. The backbone of the lignin structure is based on three types of phenyl propane units: guaiacyl, syringyl, and p-hydroxyphenyl.

Softwoods consist mainly of guaiacyl units and also to some extent of p-hydroxyphenyl units. In contrast, hardwood lignins consist of syringly and guaiacyl units.

[0044] When wood is dried, these chemical compounds that make up the structure of wood undergo various changes. In particular, according to one embodiment herein, the bait blocks 156 comprise wood dried at an elevated temperature of between about 150 degrees C (302 degrees F) and about 215 degrees C (420 degrees F), whereat these chemical changes are different from those produced by drying at lower temperature ranges, such as below about 150 degrees C (302 degrees F). In another exemplary embodiment herein, the bait blocks 156 comprise wood that is dried at an elevated temperature of between about 185 degrees C (365 degrees F) and about 215 degrees C (420 degrees F). In particular, it is believed that the heat- treated wood undergoes changes affecting the available space for air and moisture in the wood. In particular, the porosity and permeability of the wood is changed. The porosity defines the ratio of the volume fraction of void space within a solid. The permeability defines the rate of diffusion of a fluid through a porous body.

[0045] It is believed that after such treatment the porosity may increase as liquids and other compounds not strongly bound to the structure of the wood are removed with the heating of the wood, such as by evaporation. Taken alone, this change would indicate that such heat-treated wood would be more hygroscopic than untreated wood, as there is more available space within the wood. But this conclusion ignores the changes also made to the permeability of the treated wood. Permeability exists where cells and/or voids can interconnect to one another. For example, with a hardwood, intervessel pitting can create openings in membranes, allowing for improved permeability. It is believed that after such heat treatment, however, those membranes may become occluded or encrusted. Such occlusions decrease overall permeability. Moreover, the pits may also become aspirated, whereby the wood assumes a closed-cell structure that again decreases overall permeability. It is also believed that such heat treatment can cause substantial disconnection of adjacent microfibrils within the heat-treated wood. Whereas with living or non-heat-treated wood, these adjacent microfibrils provide structures for transport of liquid through the wood via normal translaminar vascular flow of phloem and xylem tissue. With their detachment, a disconnection is created within the wood that impedes the flow of liquids, thereby decreasing hygroscopy (i.e., increasing hydrophobicity). It is also believed that the increased wood shrinkage that occurs at the heat treatment temperature can lead to increased detachment of adjacent xylem tissue cells and adjacent phloem tissue cells (i.e., vascular cells), thereby inhibiting liquid passage through normal pathways of tissue cells. As would be understood by one skilled in the art, these changes depend upon the starting porosity, permeability, and density of the wood, but it is believed that such changes are generally applicable to many wood species. Moreover, such heat treatment processes may cause other changes to the structure and nature of the wood not mentioned here without departing from the scope of the embodiments of the present invention.

[0046] In addition to changes in hygroscopy and hydrophobicity, wood heat-treated in this manner also includes changes associated with other chemical compounds normally bound to the cellulose materials in the wood. While not being bound to a particular theoi , it is believed that as part of the heat-treatment process, the bonds normally binding these chemical compounds (e.g., volatile, semi- volatile, and naturally-extractable compounds (e.g., aromatic compounds), such as compounds derived from tannins, terpenes, and oils, among others) to the cellulose of the wood are broken, thereby allowing movement of the compounds more readily from the wood and into the area surrounding the wood (e.g., soil), as compared with conventional wood decay. As such, these chemical compounds may be extracted, or released, and more readily spread from the wood.

[0047] Heat-treatment of wood in this manner generally proceeds as follows. First, the wood is dried to remove a substantial portion of the liquid from the wood. In one embodiment, the drying process occurs in a range from about 110 degrees C (230 degrees F) to about 175 degrees C (345 degrees F). The dried wood is then heated to and maintained at an elevated temperature, such as between about 150 degrees C (302 degrees F) and about 215 degrees C (420 degrees F), and more suitably between about 185 degrees C (365 degrees F) and about 215 degrees C (420 degrees F). It is contemplated that in other embodiments the elevated temperature at which the wood is heat-treated may exceed 215 degrees C (420 degrees F) as long as the temperature remains below the ignition temperature of the wood specimen to inhibit charring or burning of the treated wood. The treated wood is suitably maintained at this temperature for a time sufficient to undergo the changes described above. In one exemplary embodiment, the wood is maintained at the elevated temperature for between about two hours and about three hours. The dried wood material is then cooled by a suitable cooling method such as air cooling, liquid cooling or other know method.

[0048] In one exemplary embodiment, the dried heat-treated wood may then be partially rehydrated to increase the liquid content of the cellulose material to levels of between about one percent and about eighteen percent. In still another exemplary embodiment, the heat-treated wood may be partially rehydrated to levels of between about one percent and about ten percent. In yet another exemplary embodiment, the dried wood material may be partially rehydrated to levels of between about two percent and about ten percent. It is understood, however, that the heat-treated wood need not be partially rehydrated, such that the liquid content in the dried wood is less than about one percent, without departing from the scope of this invention.

EXPERIMENTS

Experiment 1

[0049] The first experiment was conducted to determine if rodents, and particularly mice, would prefer food having heat-treated wood shavings added thereto as compared to the same food without heat-treated wood shavings. In the experiment, a control diet consisting of a matrix of cut wheat/wax/kiln dry wood shavings and a test diet consisting of a matrix of cut wheat'' wax/heat-treated wood shavings were simultaneously presented to a group of mice contained within an enclosure. The wood shavings accounted for approximately 1 percent by weight of the respective matrix. The mice had equal access to both the control diet and the test diet.

[0050] The kiln dry wood shavings and the heat-treated wood shavings used during the experiment were from the same species of tree. As discussed above, the process of heat-treating wood alters the chemical make up and material appearance of the wood. As a result, the heat- treated wood was noted as having a significantly stronger aromatic aroma as compared to that of standard kiln dried wood of the same species.

[0051] The rodent (i.e., mice) species used during the experiment was mus domesticus, BKW strain.

TABLE 1.

[0052] As seen in Table 1 , a significantly greater amount of the test diet matrix of cut wheat''wax/heat-treated wood shavings was consumed by the mice as compared to the control diet of cut wheat/wax/kiln dried wood shaving during the experiment. That is, both the male and female mice consumed more of the test diet. However, the female mice consumed a substantially larger quantity of the test diet as compared to the male mice.

[0053] The Palatability Index, which shows marked feeding consumption, can be calculated using the following equation.

Palatability Index = Total bait ingested (HTW

Total control bait ingested

[0054] Ingestion of one food material over the other was used to calculate a palatability index for each gender grouping. The calculation of the palatability index is provided above.

Experiment 2

[0055] A metal mouse trap station (prototype style) having a steep initial interior ramp with a hole on a platfonn and all metal surfaces was used in the experiment. In context of mouse interest in each station for initial discovery, all stations were nearly equal. Entry into the stations, however, was not equal with those stations that did not contain shavings of heat-treated wood. The mice would sniff around the exterior of the station without heat-treated wood but showed little to no interest in entering the station. For those stations containing heat-treated wood shavings (50 g), mice showed greater interest in each station with greater encounters where mice stepped partially into the station before backing out and had significantly greater encounters where mice fully entered the station. The previous testing with normal kiln dried Aspen shavings, mice did not respond to the addition of the wood.

[0056] Behaviorally, the mice showed a greater interest and drive to attempt entry into and climb the metal ramp immediately inside of each of the two station openings. The slope of the ramps and textures was not acceptable to unimpeded mouse entry, yet the addition of the heat- treated wood increased interest in and drive to enter the station even with the design features that were somewhat undesirable.

[0057] In view of the above Experiment, the presence of wood heat-treated at elevated temperatures may significantly enhance the efficacy of rodent stations and'Or traps that include such a wood. For example, the bait blocks 156 can comprise wood heat-treated at elevated temperatures (i.e., heat-treated wood) as discussed above. It is understood, though, that the heat-treated wood from which the bait blocks 156 is made can be in a mulch form, a powder form or other suitable form. In one embodiment, the bait blocks 156 are suitably free from toxicant. It is contemplated, however, that the bait blocks 156 can contain a toxicant (e.g., a rodenticide).

[0058] When introducing elements of the present invention or the embodiment(s) thereof, the articles "a," "an," "the," and "the" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0059] As various changes could be made in the above products and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

Claims

WHAT IS CLAIMED IS:

1. A method of controlling rodents comprising:

locating a wood that has been heat-treated to a temperature of greater than about 150 degrees C in an area accessible to rodents; and

at least one of monitoring the heat-treated wood for the presence of rodents and locating a rodenticide in the area.

2. The method set forth in claim 1 wherein the heat-treated wood is in a particulate form.

3. The method set forth in claim 1 wherein the heat-treated wood comprises compressed cellulose powder.

4. The method set forth in claim 1 further comprising setting a rodent trap and locating the heat-treated wood in association with the trap to attract rodents to the trap.

5. The method set forth in claim 1 wherein locating the rodenticide in the area comprises locating the rodenticide adjacent to the heat-treated wood.

6. The method set forth in claim 5 further comprising placing a rodent management station with the area, the rodent management station comprising a housing having an interior space, wherein locating the heat-treated wood comprises positioning the heat-treated wood in the interior space of the housing, and locating the rodenticide comprises placing the rodenticide in the interior space of the housing adjacent to the heat-treated wood.

7. A method of controlling rodents comprising:

locating a toxic bait comprising wood that has been heat-treated to a temperature of at least about 150 degrees C and a rodenticide within an area accessible to rodents.

8. The method set forth in claim 7 wherein locating the toxic bait comprises locating in the area a bait comprising a rodenticide and wood that has been heat-treated to a temperature of at least about 185 degrees C.

9. The method set forth in claim 7 wherein locating the toxic bait comprises locating in the area a bait comprising wood that has been heat-treated to a temperature of greater than about

150 degrees C and has a moisture content of less than about ten percent, and a rodenticide.

10. A method of controlling rodents comprising:

locating a rodent management station in an area accessible to rodents, the rodent management station comprising a housing and at least one opening therein providing communication between an interior and the exterior of the housing;

positioning a trap within the interior of the housing; and

placing a heat-treated wood in the interior of the housing, the heat-treated wood comprising wood that has been heat-treated to a temperature of greater than about

150 degrees C.

1 1. The method set forth in claim 10 wherein the heat-treated wood is in the form of a particulate.

12. The method set forth in claim 10 wherein the heat-treated wood is compressed into blocks.

13. A rodent attractant for use in monitoring and controlling rodents, the attractant comprising a heat-treated wood, the heat-treated wood comprising a wood that has been heat treated to a temperature of greater than about 150 degrees C.

14. A rodent trap assembly comprising a trap and a heat-treated wood for attracting rodents to the trap, the heat-treated wood comprising wood that has been heat-treated to a temperature of greater than about 150 degrees C.

15. A toxic rodent bait comprising a heat-treated wood and a rodenticide, the heat-treated wood comprising a wood that has been heat treated to a temperature of greater than about 150 degrees C.