Do Bats Hibernate?

Bats are Unique Flying Animals That Don’t Typically Migrate

Many people wonder where bats live throughout the year, including during winter.

All bats found in Massachusetts and throughout most of New England are insectivores that feed primarily at night, catching thousands of mosquitoes, moths, and other night-flying insects.

It is estimated that an individual bat can eat 600 insects per hour. Bats must consume a lot of insects to fuel their daily activities, especially flying, as bats are the only mammals that truly fly.

When cold weather drives insects away, bats must choose to hibernate or migrate to warmer areas with more abundant food supplies. Some bat species hibernate, some migrate, and some do both.

Bat Behavior in Different Climates

In temperate climates, like Florida, bats may be able to stay active year-round.

In the Northeast, the two most common bats are the little brown bat and big brown bat.

Little brown bats, listed as an endangered species, migrate to hibernation caves and mines, mainly in New England. Big brown bats, which are more tolerant of cold temperatures, may migrate to caves or spend the winter in the same buildings they occupy the rest of the year.

Buildings, such as your home, give bats what all mammals need: protection from predators, stable temperatures, and safe shelter where they can rest and raise their young.

Buildings are also usually much warmer than other hibernacula, potentially making them an ideal spot to wait out the winter.

What Actually is Hibernation?

Hibernation is a state of prolonged torpor involving an extreme reduction in metabolic rate, heart rate, and respiratory rate that allows a bat to survive long periods of time without food.

A bat’s heart rate drops from 200 to 300 beats per minute to 10 beats per minute, and it may go minutes without taking a breath. A bat’s body temperature can also drop to near-freezing, depending on the temperature of the bat’s surroundings.

Other bodily functions also slowdown in this state of torpor and a bat can lose as much as half of its body weight during this time. This maintains the bat’s energy level at 2 percent of normal life functions and allows it to survive for up to six months on a very small amount of stored body fat.

Bats may enter torpor for just a few hours to save energy during a cold day, or they can remain in torpor for up to a month while hibernating over winter. During hibernation, bats cycle through periods of torpor interrupted by brief periods of arousal when their body temperatures return to normal for a few hours.

Some species, such as the little brown bat, may hibernate for more than six months waiting for the return of insects in the spring.

What Do I Do if I Find a Bat in my House?

Because bats are so efficient at controlling many of the insects people find bothersome, it is advantageous to leave them alone. That being said, there are instances where a bat is not welcome, such as inside your home.

Successfully evicting a bat that accidentally ended up in your house can be challenging, and hitting the bat or throwing things at it will cause it to become disoriented making it harder for the bat to find its way out.

The best action to remove a single bat is to open a window or door in the room containing the bat, close off the rest of the house, and block the space under the door with towels. A flying bat will usually circle the room several times until it locates the open window and flies out.

If you think you have multiple bats living in your house, especially hibernating bats, know that Massachusetts requires non-lethal approaches using one-way doors. Poison and other methods are illegal.

Since bats are protected in Massachusetts, attempts to evict a colony of bats can only be made during the mid-spring (during the month of May), or late summer (from August to mid-October).

Contacting a knowledgeable professional who understands bat behavior and laws protecting bats may be your best option for removal. Catseye Pest Control offers no-cost inspections, so contact us anytime.