There are forty species of bats in the United States, each species with distinctive physical characteristics.

Bats are the only mammals capable of actual flight.

Bats are nocturnal. They hunt at night and roost during the day in trees, bat boxes, under eaves, and in buildings where they can gain access through open spaces in the roof, attic, or walls.

Bats are insectivores and live around fresh water where such insects can be plentiful.

Bats are most active in the spring and summer and many migrate or hibernate during the winter.

Bats are not blind, but have fairly good eyesight. They navigate and find food primarily by using a sonar system known as echolocation.

Most bats give birth to a single baby which is unable to fly for several months. Babies cling to their mothers until they are too large to be carried, and are then left behind in a nursery colony while the adults hunt. Accessible attic spaces, which are often warm and dark, are sometimes used as nursery sites until the babies are old enough to fly on their own.

For centuries, bats have been the victims of negative mythology, but in reality they are useful predators and help to control insects. A single little brown bat can consume up to 3,000 mosquitoes every night.

Healthy bats prefer to keep their distance from humans - the stories about bats becoming entangled in people's hair are myths. However, there are rare instances of rabid bats biting humans and other animals. If you find a sick or injured bat, contact the PAWS Wildlife Center (if you live in King or Snohomish Counties) or your local wildlife rehabilitation center elsewhere in western Washington for assistance.

Never attempt to pick up a bat with your bare hands.

Bats can be rabid, although this is an exaggerated danger. There are only a very few cases in the US of transmission from bat to human. Possible signs of rabies include the inability to fly and activity during daylight hours. Another warning sign is being present around people and the noise of human activity, all of which a normal bat will seek to avoid. Rabid bats may also be lethargic, which unfortunately renders them docile and approachable.

If you or a domestic animal in your care is bitten, or if material such as saliva or droppings comes in contact with your eyes, nose, mouth, or a cut of any kind, wash the area thoroughly with soap and water and seek medical advice immediately.

Some bats will bite and leave little obvious trace. If you awaken and find a bat in your living area, or near a child, or a handicapped or impaired person, seek immediate medical advice. If you think a domestic animal has been similarly exposed, immediately take the animal to a veterinarian.

Like other wild animals, bats sometimes find their way into buildings. They do not chew or dig their way in, but are able to squeeze through cracks and holes as small as 3/8" wide. Damage caused by bats is usually minimal, but the smell of their droppings can be offensive.

If you discover a bat in your living space, remain calm and provide a way for the animal to leave the house. Close interior doors, turn out the lights, open a door or window, and wait for the bat to locate the exit. If the bat is found during the day, you might have to wait until nightfall before the bat leaves. Once the bat is gone, determine how it entered, checking for possible entry points around door and window casings, air conditioners, vents, and chimneys. If you are sure there are no other bats in the house, seal all holes and cracks.

If you suspect that a colony of bats has taken up residence in a wall or attic space, watch for bat activity at nightfall and look for telltale signs of accumulated droppings below the entry.

The best strategy for bat-proofing is:

1. Allow the bats to leave on their own. Do not use repellents because they will drive the animals further into the house. From May until late August, assume there are juveniles in the space, and wait until the babies are old enough to fly out with the adults.

2. Make certain that there are no remaining bats in the space. At the end of the summer when you are certain that there are no more young, begin excluding the bats by closing off all available entries. Leave one hole open, and fit it with a one-way door, similar to a cat door, with a hinged flap so that bats can escape but not re-enter the space. Leave this in place for several days, continue to watch for bat activity, and if possible inspect the space until you are certain that they are gone.

3. Permanently exclude bats by sealing all possible entries. Caulk cracks during warm, dry weather when cracks are the widest. Use weather stripping to seal spaces around doors, windows, and vents, and replace loose boards and roofing materials. Be sure to secure every crack and hole in outside walls, eaves, and roofs.

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