Wildlife Damage Management, Internet Center for

 

Date of this Version

January 1994

Abstract

Despite their ecological value, bats (Myotis lucifugus) are relentlessly and unjustifiably persecuted. Bats, the only mammals that truly fly, belong to the order Chiroptera. Bats in North America are virtually all insectivorous, feeding on a variety of flying insects (exceptions among house bats were noted previously). Most North American bats emit high frequency sounds (ultrasound) inaudible to humans and similar to sonar, in order to avoid obstacles, locate and capture insect prey, and to communicate. Bats often fly about swimming pools, from which they drink or catch insects. Bats use roosting niches that are indoors (human dwellings, outbuildings, livestock quarters, warehouses), semi-enclosed (loading docks, entrance foyers), partially sheltered (porches, carports, pavilions, highway underpasses, bridges), and open structural areas (window shutters, signs). Surface areas on walls, under loose woodwork, between bricks and around other bat entryways often have a smooth, polished appearance. Disturbing sounds may be heard from vocalizations and grooming, scratching, crawling, or climbing in attics, under eaves, behind walls, and between floors. Fecal pellets indicate the presence of animals and are found on attic floors, in wall recesses, and outside the house at its base. Several arthropods (fungivores, detritivores, predators, and bat ectoparasites) are often associated with colonies of bats in buildings. Bats are distinct from most vertebrate pests that inhabit human dwellings because of the potential for transmitting rabies — a viral infection of mammals that is usually transmitted via the bite of an infected animal. Rabies is the most important public health hazard associated with bats. The lethal control of bats, even when there is a proven potential danger to humans, often is subjected to careful scrutiny and interagency coordination.