Little Brown Bat - Watchable Wildlife - NYS Dept. of Environmental Conservation

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Little Brown Bat - Watchable Wildlife

Did You Know?

little brown bat roosting in a cave
Little brown bat - Myotis lucifugis
  • Bats are the only mammals that can fly.
  • They are insect-eating machines, eating thousands of mosquitoes and other flying insects in a single night!
  • Bats use echolocation (rapid pulses of sound that bounce off an object) to detect and catch insects. They scoop the insects up in their tail or wing membranes and then place them in their mouth. This is what gives them such an irregular flight pattern.
  • As temperatures decrease in the fall and the number of insects diminish, bats migrate to their hibernacula (place where animals hibernate) in caves or mines for the winter. During hibernation a bat will reduce its body temperature. It will slow its heart rate to only one beat every four or five seconds and rely on its stored fat reserves to survive until springtime.
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What to Watch for:

Size:

Little brown bats have a wingspan of 8-9 inches and a body length of 3-4½ inches with a 1 ½ inch forearm.

Appearance:

They are covered in a coat of silky cinnamon and dark brown hair and pale grey underneath. They have black hand-like wings.

Where to Watch:

Bats can be found in caves and mines during the winter, but do not look for bats in these areas. Entering into caves or mines is dangerous without the proper knowledge or guidance. White-nose syndrome is a serious disease in bat populations that can be spread from cave to cave by humans (see below). In addition, it is important not to disturb and awaken hibernating bats in the winter, because they will lose necessary fat reserves that they rely on to survive.

What to Listen for:

Bats make sounds by echolocation, which are generally too high pitched for the human ear to hear. You may be able to hear a click or squeak as they fly by directly overhead.

When to Watch:

In the spring or summer, during early dawn or dusk, look up above a body of water (lake, pond, stream, etc.) and/or among trees. You may see them flying back and forth and dipping and diving for insects. Looking in areas where flying insects are most abundant, usually in areas near water, provides a good chance to spot bats.

More Information About Little Brown Bats:

How to safely remove a bat from your home: Do not attempt to handle a bat under any circumstances. If provoked or threatened, just like any other animal, bats will defend themselves, typically by biting. In general, bats are not dangerous animals and are very beneficial to our environment. Harming or killing these animals is wrong and unnecessary.

  • A bat in flight in your home: Turn on some lights in order to see the bat. Close doors to other rooms of the home in order to restrict the bat's access to a small area. Open all exterior windows or doors in the room. The bat can then use its echolocation to navigate a safe path outside.
  • Bats roosting (resting) in your home: The best solution is to contact a wildlife damage control company. Do not attempt to exclude bats during the winter while they are hibernating. Instead, wait until the spring and summer when they are active. Make sure the site is clear of any hibernating bats before sealing all potential entry points into your home spaces.
  • Build or buy a bat house to keep bats out of your home. See How to Build a Bat House (PDF 138 KB).
bat box example
Homemade bat house

The Best Places to See Little Brown Bats: