Managing Bats in Your Living Space


This Halloween season, arm yourself with the best strategies for managing bats in living spaces, attics and barns.  Bug-eating bats are important to a healthy environment, and many people have a few bats in their attic and never know it. However, a large colony can become a nuisance, and bats should be kept out of interior living quarters.  Now is a good time to seal up entry points and clean-up bat droppings as New Hampshire’s eight species of bats migrate south or hibernate in the colder months. Here are some facts and  tips:

First, a few facts about bats. These small flying mammals can eat up to 1,200 mosquitoes per hour, and will eat their body weight in bugs in a single evening. Bats are nocturnal, so it is best to try to vacate them in the evening. Bats can see during the day, but their activity is highly limited. Bats must drop from a high spot in order to fly: they cannot lift off from the ground. If trying to remove a bat that is on the floor, give the animal time to climb up and gain height before expecting it to fly out!

A bat loose in your living space: Take a deep breath, put on some gloves and remind yourself that the bat wants to get out. Never touch a bat with your bare hands. Open a window, turn off inside lights, turn on the outside lights and close interior doors to prevent the bat from moving to another interior space. Usually within 20 minutes or so the bat will find its way out. Do not use a broom or tennis racket to assist! In the fall or winter, the big brown bat is the one local species that, at times, hibernates in buildings; one may awake to look for a snack and surprise you. In colder months, try to release a trapped bat during a warm time of day if possible.

Preventing their return to your attic:  Mothballs hung in an old stocking or bright lights can be deterrents, but the best strategy is blocking access.  Chimneys, cracks or holes in the siding or soffits, or just about any place where materials have moved apart, invites bats to enter and make themselves at home. If you don’t know where they are getting in, watch for their movements in and out of your house in the summertime at dusk.

Relocating the bats:  If you evict bats, they need somewhere to go. Consider installing a bat house on your property.  The boxes are varied shapes and look like big birdhouses.
Cleaning up after bats:   Bat manure, or guano, can contain a fungus that can sometimes cause a respiratory infection in humans, so proper precautions are necessary. In a barn or space that is difficult to close up, owners might need to come up with a strategy for managing guano instead of removing bats. Some barn owners tarp large sections of equipment or insert a tarped “ceiling” that can be removed and cleaned periodically.  

Thanks to the N.H. Fish and Game Department and Preservation Alliance members for information for this article. More on all aspects of bat management: batworld, Fish and Game,  and more old house tips on our website.
A Halloween P.S.: Bats are nocturnal creatures, so it’s natural that a celebration about the end of the light seasons and the beginning of the dark ones would incorporate them.  Additionally, in the old days Halloween meant big bonfires, which draw mosquitoes and moths, which would in turn draw bats, so bats were likely a common sight during the early Samhain festivals and later Halloween celebrations.