the cactus wren (campylorhynchus brunneicapillus) is a species of wren that is native to the southwestern united states southwards to central mexico .
the cactus wren primarily eats insects , including ants , beetles , grasshoppers , and wasps .
occasionally , it will take seeds , fruits , small reptiles and frogs .
foraging begins late in the morning and is versatile; the cactus wren will search under leaves and ground litter and overturn objects in search of insects , as well as feeding in the foliage and branches of larger vegetation .
increasing temperatures cause a shift in foraging behavior to shady and cooler microclimates , and activity slows during hot afternoon temperatures .
almost all water is obtained from food , and free-standing water is rarely used even when found (udvardy 1994; ricklefs 1968; mccarthey 2000) .
it is a bird of arid regions , and is often found around yucca , mesquite or saguaro; it nests in cactus plants , sometimes in a hole in a saguaro , sometimes where its nest will be protected by the prickly cactus spines of a cholla or leaves of a yucca .
the cactus wren forms permanent pair bonds , and the pairs defend a territory where they live all through the year .
in residential areas , cactus wrens are notorious for getting into mischief .
being curious birds , it is not uncommon for these wrens to be found flying about out-of-place in automobiles where the owner has left a window open or it may even enter homes with an open door or window and find itself trapped .
