Why Is There a Bat in My House in the Winter?
This is a question we’ve been answering lately as wayward bats have been found in bathrooms, bedrooms, and basements here in the Akron / Canton / Kent area.
This post takes a look at winter bat activity, specifically that of the big brown bat.
Most of us were raised with the (mostly correct) idea that bats hibernate in the winter here in Ohio. In fact, I just asked a 6 year old bat afficianado sitting next to me what bats do in the winter. He quickly responded, “They hibernate. That means they sleep through the whole winter.” As he made the last statement, he made a big sweeping gesture with his arm.
And while it is proper to classify local bats as hibernators, our research and experience has informed us that “hibernation” is a generic term that should be understood with more nuance. People who call us after finding a bat in the bathroom fan will tell you they weren’t “sleeping” the whole winter.
So what’s going on when people find a very awake bat in their home? Why wasn’t the bat currently hibernating?
Big Brown Bats Have Short Periods of Activity
A “sleepy” December Big Brown Bat
Once the temperature drops (as it did drastically this November), bats seek places with stable temperatures to hibernate. Some species migrate or go to caves to hibernate en masse. But a very common bat species here in the Akron / Canton / Kent area, the big brown bat, is well known to hibernate in buildings. They’ll hibernate as individuals or in small colonies. These buildings where we are called for winter bats may very well have had bats roosting in them throughout the year.
Once in their spots for hibernation, their metabolism is lowered drastically to conserve energy reserves (body fat) to make it through a winter without insects. This condition of inactivity and low metabolism is known as torpor. During this period of inactivity, their presence is rarely revealed to homeowners.
But while they are metabolically depressed most of the time, biologists have collected lots of data showing that they raise their activity level from time to time all through the winter. It is during these short periods (usually just a few hours) of increased activity that they are revealed to unsuspecting homeowners.
Why do they come out of torpor for short periods of time?
- Temperature fluctuation. Stability is best for bats. If it gets warmer they may rouse to look for food because some insect species may be present. If it gets too cold where they are at, they may move to look for more warmth. We often get more calls the warmer it gets.
- Excretion or water intake
- Disease: A fungal infection, white-nose syndrome, has been wreaking havoc on hibernating bat populations in recent years as presence of the syndrome is related to bats rousing too often, using up their energy reserves.
- Disturbance of some kind (like homeowners getting Christmas decorations out of an attic)
A truly definitive answer for why a specific big brown bat is on the move in your home is elusive. However, we and homeowners who’ve had winter bats in their living spaces know it happens and needs addressed.
What to Do About Winter Bats in Your Home?
If you find a bat in your home this winter, we suspect you’ve found this blog post because you’d like it removed.
If you are in our area, call us and we’ll come and pick the bat up and remove it from your living space.
After removal, you’ll want to consider how the bat got where it was found. If it came through a chimney, vent, or other access point, these weak spots can be screened to keep others out of your living spaces.
That being said, we strongly encourage you to let any other bats found in a non-living space (like the attic) be left alone.
Prolonged metabolic arousal and eviction during this time of year takes too much energy from the bat. Without food, they aren’t able to replace it and though they might fly away and find another spot to shelter in, they will most likely not make it through the winter. Bat conservation is important.
For more on Bats and Bat Removal here in the Canton / Kent / Akron area check out some of our other site resources on bats.
