referring now to fig1 through 6 , numeral 10 designates generally a housing structure constructed in accordance with the teachings of the present invention . for purposes of example only , the embodiments of the present invention shown in the figures relate to the construction of houses for ducks or other birds . the principles of the present invention can , however , be applied to the construction of a housing structure for any cavity - dwelling animal . [ 0023 ] fig1 is a front plan view of an embodiment of a birdhouse constructed in accordance with the teachings of the present invention . birdhouse 10 includes a housing unit 11 , which includes a roof , four walls , and a floor . the floor of housing unit 11 is provided by a floor member 12 . the lower surface of floor member 12 serves as the base of the birdhouse . the upper surface of floor member 12 serves to provide a solid floor for the interior of the birdhouse upon which birds may construct nests and the like . extending upwardly from floor member 12 , and substantially perpendicular thereto , are side wall members 14 and 16 . side wall members 14 and 16 extend substantially along the length of floor member 12 . roof 20 contacts the upper surface of side wall members 16 and 1 4 , enclosing the top portion of the birdhouse . roof 20 may be constructed of a unitary piece of material , bent at a midpoint to form a “ v ” shape , or may be constructed of two smaller components fixedly attached so as to form a “ v ” shaped roof member . front wall member 18 extends upwardly from a front portion of floor member 12 to a front portion of roof 20 . front wall member 18 has an opening 22 that is sized , shaped , and located according to the type of bird that the birdhouse is meant to attract . a rear wall ( not shown ) extends upwardly from a rear portion of floor member 12 to a rear portion of roof 20 . the rear wall is sized and shaped substantially similar to front wall member 18 , except that the rear wall preferably does not contain an opening . the size of opening 22 may vary according to the type of bird the birdwatcher wishes to attract . for example , small birds such as chickadees or nuthatches may nest in a birdhouse having an opening 1 to 1 ¼ inches in diameter . purple martins or woodpeckers may require an opening of 2 to 2 ¼ inches in diameter . large birds such as barn owls may require an opening of up to 6 inches in diameter . opening 22 should be as small as possible while still allowing the desired bird type to enter , because smaller holes make it more difficult for many predatory animals to enter the birdhouse and also discourage certain “ pest ” birds such as starlings . [ 0026 ] fig2 is a side plan view of an embodiment of a birdhouse constructed in accordance with the teachings of the present invention . an opening 24 is provided in side wall 14 . opening 24 provides a mean by which a birdwatcher can view birds inside of birdhouse 10 . opening 24 is preferably , but not necessarily , covered with a sheet of transparent material 40 , as best shown in fig3 . the presence of the transparent material 40 prevents nestlings from falling from birdhouse 10 through opening 24 and also prevents pests and predators from entering birdhouse 1 0 through opening 24 . this opening 24 can be of virtually any design with the illustrative embodiment being a heart design . the transparent material 40 may be secured to the inside of side wall 14 by glue or any other suitable means , such as velcro ®, staples or brads and the like . velcro ® is a federally registered trademark of velcro industries b . v ., having a place of business at castorweg 22 - 24 , curacao , netherlands . if the transparent material 40 is secured to the inside of side wall 14 by glue or any other fixed adhesive , then preferably , the entire side wall 14 is removedly attached from the entire birdhouse 10 with velcro °, staples or brads and the like . this allows for the retrofitting of conventional birdhouses . although the transparent material 40 is preferably plexiglas ®, traditional glass as well as a wide variety of transparent materials will suffice . this transparent material 40 can be etched , clear , painted , imitation stain glass among numerous other modifications in color and design . [ 0027 ] fig4 is a front plan view of an alternative embodiment of a birdhouse , designated generally by numeral 26 , constructed in accordance with the teachings of the present invention . birdhouse 26 comprises a housing unit 27 , which includes a roof , four walls , and a floor . the floor of housing unit 27 is provided by a floor member 28 . the lower surface of floor member 28 serves as the base of the birdhouse . the upper surface of floor member 28 serves to provide a solid floor for the interior of the birdhouse . extending upwardly from floor member 28 , and substantially perpendicular thereto , are side wall members 30 and 32 . side wall members 30 and 32 extend substantially along the length of floor member 28 . roof 36 contacts the upper surface of side wall members 30 and 32 , enclosing the top portion of birdhouse 26 . in this embodiment , roof 36 is a unitary , flat member positioned parallel to floor member 28 along the upper surfaces of side wall members 30 and 32 . front wall member 34 has an opening 38 that is sized , shaped , and located according to the type of bird that birdhouse 26 is meant to attract . a rear wall ( not shown ) extends upwardly from a portion of floor member 28 to a rear portion of roof 36 . the rear wall is sized and shaped substantially similar to front wall member 34 , except that the rear wall preferably does not contain an opening . side wall 30 is substantially similar to side wall 14 , as shown in fig3 and described above , having an opening 24 through which a birdwatcher may observe birds within birdhouse 26 . the opening 24 of side wall 30 is also preferably , but not necessarily , covered with plexiglas ® or other suitable transparent material to prevent nestlings from falling out of birdhouse 26 and to prevent predators and pests from entering . [ 0030 ] fig5 is a front plan view of a second alternative embodiment of a birdhouse , indicated generally by the numeral 42 , constructed in accordance with the teachings of the present invention . birdhouse 42 is similar in general structure to the embodiments above , essentially being a housing unit 43 comprising a floor member 44 , opposing side wall members 46 and 48 , a roof member 50 , a front wall 58 , and a rear wall ( not shown ). the structure of the front wall of birdhouse 42 is , however , different from the two embodiments previously described . front wall 58 has an opening 52 that is sized , shaped and located according to the type of bird that birdhouse 42 is meant to attract . front wall 58 , however , is constructed of a plurality of solid , opaque members 56 made of wood or other suitable materials , and a plurality of solid , transparent members 54 , preferably , but not necessarily , made of plexiglas ® or other transparent materials . transparent members 54 allow a birdwatcher to view the interior of birdhouse 42 , and any animals therein , from the front . [ 0032 ] fig6 is an exploded front view of the first embodiment described above of a birdhouse 10 constructed in accordance with the teachings of the present invention . roof 20 is shown removed from the remainder of housing unit 20 so that light bulb 60 , located in the interior of birdhouse 10 when birdhouse 10 is assembled , can be seen . light bulb 60 is removably attached to socket 62 , which is , in turn , attached to the underside of roof 20 . a nonlimiting example of a socket 62 can include a bayonet lamp base , e . g ., radio shack ® model 272 - 359 and a nonlimiting example of a light bulb 60 can include a bayonet lamp bulb , e . g . radio shack ® model 272 - 1108a . a pair of wires 64 extends from socket 62 through an opening in roof 20 and to a power source ( not shown ). the presence of light bulb 60 allows a birdwatcher to illuminate the interior of birdhouse 10 for the purpose of viewing the interior thereof . the light cast by light bulb 60 produces a glare along the interior surface of transparent material 40 , thus rendering any birds within birdhouse 10 incapable of seeing the birdwatcher and preventing them from becoming alarmed . the light bulb configuration shown in this embodiment may be used with any of the above embodiments of the present invention . moreover , any of a wide variety of light bulbs and associated power supplies may be utilized with the present invention . also , more than one light bulb 60 can be located within the birdhouse 10 in a wide variety of locations and configurations . referring now to fig7 an illustrative , but nonlimiting , power supply is generally indicated by numeral 100 , which is preferably child safe for indoor and outdoor usage . an illustrative housing preferably , but not necessarily , includes a housing 106 , e . g ., radio shack ® project enclosure model 270 - 1807 that is fastened by screws 108 . the battery can be of any type and is preferably a standard nine ( 9 ) volt battery that is generally indicated by numeral 102 and secured in position with a battery holder 104 . however , any of a wide variety of batteries will suffice in this application , e . g ., 6 . 3 volt lantern battery , nickel cadmium battery , and so forth . the power supply 100 can be located within the birdhouse or a considerable distance away from the birdhouse . an advantage to locating the power supply away from the birdhouse is that the power supply can be protected in more environmentally favorable conditions . an alternative current power supply can also be utilized instead of a lantern . this battery holder 104 can preferably , but not necessarily , include a velcro ® is a federally registered trademark of velcro industries b . v ., having a place of business at castorweg 22 - 24 , curacao , netherlands . a battery connector 116 may be utilized to provide power from the battery 102 . a nonlimiting example of this illustrative type of battery connector is a radio shack ® model 270 - 325 . optionally , there is a pair of micro alligator clips 120 and 122 , e . g ., radio shack ® model 270 - 373b that connects to pair of wires 128 and 126 . wire utilized with the present invention is preferably , but not necessarily 22 gauge wire . wire 126 can be connected to an on / off switch that is generally indicated by numeral 132 . this preferably can include a rocker , single pole , single throw switch , e . g ., radio shack ® model 275 - 693 . from the on / off switch 132 there is a wire 129 that connects to a connector terminal 131 . a nonlimiting example of a connector terminal 131 includes a speaker terminal board , e . g ., radio shack ® model 274 - 622a that is severed in half and attached to the housing 106 by pair of screws 130 . an optional rope cleat 140 may also be attached to the housing 106 . from the terminal connector 131 extends the aforementioned pair of wires 64 , as shown in fig6 . radio shack ® is a federally registered trademark of trs quality , inc ., having a place of business at 1700 one tandy center , p . o . box 17180 , fort worth texas 76102 . another alternative embodiment of one aspect of the present invention is shown in fig8 and indicated generally by the numeral 200 . shown is an interior side wall 210 having an opening 212 for viewing the interior of the housing structure . opening 212 is preferably , but not necessarily , covered with a transparent material . also provided with side wall 210 are two access ports 214 for allowing access to the interior of the structure . access ports 214 may be covered with flaps or other structures to prevent them from being completely open when not in use by a person accessing the interior of the housing structure . when no one is either accessing the interior of the housing structure or viewing the animals therein through opening 212 , an exterior side wall , or cover , 220 is provided to cover interior side wall 210 . this allows for greater comfort and security on the part of animals dwelling within the structure in that they are not alarmed by the presence of an obvious opening in the side of the structure . exterior side wall 220 can be attached to interior side wall 210 by hinges , pins or any other suitable means of attachment . though a side wall structure is provided in the drawings , the same principles may instead be applied to the construction of a rear wall for the housing structure . for instance , the opening provided for viewing , as well as the access ports , may be provided in an interior rear wall and an exterior rear wall may be provided to cover the openings when not in use . [ 0038 ] fig9 provides still another alternative embodiment of a side or rear wall of the present invention , designated generally by the numeral 300 . this embodiment includes access ports 310 with gloves 320 attached thereto . gloves 320 are attached to the interior of wall 300 such that a user can insert his hands through access ports 310 and into gloves 320 . the user can then easily manipulate objects within the interior of the housing structure . this embodiment is particularly useful for conservationists who may wish to check , for example , eggs within the structure for hardness , or gather eggs for incubation purposes , as well as for health officials dealing with animal populations that are carriers of human disease . a housing structure constructed in accordance with the present invention may be constructed of any suitable material . wood is preferred , however plastics and metals and the like may also be used . the precise material used to construct a birdhouse may vary depending on the type of bird that the birdhouse is meant to attract . likewise , the precise structure , shape and configuration of the birdhouse may also vary depending on the type of bird desired . the shape of the side wall openings , such as opening 24 described above , may be any suitable shape , including any number of fanciful configurations such as the heart shape illustrated in the above embodiment . in each of the above embodiments , the roof or one of the side walls of the birdhouse may be detachable to allow access to the interior of the birdhouse . thus , a birdwatcher may clean the interior of the birdhouse after each brood of nestlings has fledged . the roof or side walls may be entirely detachable or may be positioned on hinges and held closed with a clasp ( not shown ) that may be opened by the birdwatcher . thus , there has been shown and described several embodiments of a birdhouse constructed in accordance with the teachings of the present invention . many changes , modifications , variations , and other uses and applications of the present constructions will , however , become apparent to those skilled in the art after considering this specification and the accompanying drawings . all such changes , modifications , variations , and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited by the claims which follow .
a housing structure that includes a transparent opening in one wall thereof , the opening being covered with a transparent material such as plexiglas ®. this opening allows a user to view the interior of the structure and ascertain the welfare of any animals within or check for pests without opening the birdhouse and risk frightening or harming the animals . in addition , the housing structure may also include a light within such that a user can illuminate the interior thereof . this allows the user to inspect the interior of the structure when it is too dark to do so without the help of an artificial light source . moreover , the structure may include a removable roof or side wall for easy access to the interior of the birdhouse for the purpose of cleaning and the like , or access ports that may be used to access the structure without opening .