Fact Sheet for Bat Inspection in Homes

It is not unusual to find bats in homes in New York State, and the presence of bats usually does not result in a need for rabies postexposure prophylaxis. Most (97%) bats tested at the NYS Wadsworth Center's Rabies Laboratory are negative for rabies. However, because many of the human rabies cases in the United States since 1990 appear to have acquired their disease from an unrecognized bat bite in a home situation, all reasonable steps should be taken to keep bats out of the home environment, especially sleeping quarters.

  • not leaving unscreened doors open to the outside
  • not leaving unscreened windows open to the outside
  • making sure windows have screens, chimneys are capped, and electrical and plumbing openings are plugged
  • sealing up all openings larger than 1/2 inch by 1/2 inch square into the attic, basement, walls, or occupied areas of the house
  • using materials such as expanding spray-on foam, caulk, wire mesh, wood that fits tightly, steel wool (around pipes that enter buildings), or polypropylene bird netting, to seal or cover gaps and holes

  • hearing squeaking noises coming from attic, walls, or elsewhere
  • inspecting attic space, rafters, porches, and walls for signs of roosting bats, including bat guano and crystallized urine, or bare scratched areas on beams
  • walking around the outside of the house at dusk to see if bats are flying out of the house to feed, or before dawn to see if bats are flying into the house to roost

  • killing or poisoning the bats is seldom a necessary or desirable solution
  • openings should not be sealed while bats are inside--this may drive them into occupied areas or create a sanitary problem if the bats are trapped and die inside
  • major home renovations and sealing should be done during the winter when bats have mostly left buildings
  • the bats' entry and exit points should be determined by observing the house at dusk or dawn as described above
  • special netting can be used in a manner that allows bats to exit a house, but not re-enter
  • pest control experts specializing in bat control should be consulted when necessary