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Brown Bat

Scientific name: Myotis Lucifugus

This little brown bat is an important member of our local ecosystem. Their ability to consume large numbers of insects, during dawn and dusk of  the summer months, help to control their numbers. For example, the mosquito can spread various diseases and the bat is nature’s way of keeping them in balance.

The wings of the bat are actually a thin membrane which is attached to what are elongated finger bones. Each membrane has four fingers and a thumb. They have soft fur covering their bodies.

A disease, known as white nose syndrome (WNS), has been responsible for the deaths of enormous numbers of bats. A white fungus forms on their noses while hibernating, causing them to die. The cause is unknown. For more information on this serious disease, read here.


They are 3 to 4 1/2 inches long and have a wingspan of 8-9 inches.

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How do Bats Fly in the Dark?

Bats do have very good vision, but at night they navigate using echolocation. When flying, they emit very high frequency sounds which are beyond our range of hearing. The sounds bounce back to them, allowing them to locate insects, for example. They can also change the frequency of the emissions from 20 to 500 pulses per second, in order to close in on their prey!


Bats are insectivores and can eat up to 600 insects per hour during the time they are feeding! Mosquitoes, moths and other night flying insects are all part of the bats’ diet.

Life Cycle

Bats mate in the fall, and the sperm stays within the uterus of the female until spring, when hibernation is over.  A single baby bat is born in June or July. During the first weeks of life, she clings to her mother during flight. By the time the bat is a month old, they are able to hunt on their own. By fall, the bat will look to either migrate or hibernate in place.

Similar Species

Read about the bats of New York here.

Human Connections

Sometimes, a bat will enter the house. It is possible to have a professional remove them, or read the info in the next paragraph.  Of course, if you think that you may have been bitten, it is necessary to seek medical advice!

The NYS DEC has the following recommendations on its website.


The little brown bat needs temperatures ranging from 30-40 degrees during the winter months. Often, they hibernate by the thousands in abandoned mines or caves. It is during this period of time where they are vulnerable to the white nose disease. Some bats will stay in their habitat if they have a warm enough structure.

Fun Facts

Did you know that the bats’ breathing slows to one breathe every five minutes while hibernating?

How You Can Help

You can learn to build a bat box to put in your own backyard ! Learn how here.

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