Do you have bats living in your barn or house?

Both of the species of bats most commonly found in NH attics and barns--Little and Big Brown bats--will take to bat houses.  Hang them under eaves over areas where you won't be bothered by guano (bat poop, and a good fertilizer), but where they will receive lots of sun and shelter from the elements.  You may have to experiment over a few summers before finding a successful location!

Many bat species are dying from a new disease called White Nose Syndrome.  Thousands upon thousands of bat lives have been lost since the disease was first detected in the northeast in the winter of 2008.

The following is an excerpt from a Speaking For Wildlife presentation that I have given as part of my volunteerism for the NH Coverts Project.  It was written by NH Fish and Game wildlife biologist Emily Brunkhurst and USFWS wildlife biologist Susi Von Oettingen, and is intended to provide homeowners some low cost, easy solutions for problems they find come with having bats, but also for providing bats the critical support they need now:

Have you ever had bats living in your house or barn? Finding solutions to the problems bats can cause without removing them from where they live is an important thing you can do for bats:


• Bats in your attic is a problem that usually can only be remedied by excluding bats from the house. If you are uncomfortable with bats in your attic, you can hire a licensed wildlife control operator to do an exclusion (or you can do it yourself). They will put up a 1-way device over the holes where bats enter your house, so the next time they fly out they cannot get back in. After the bats are all gone, you can seal up the holes. However, from mid-May through mid-August the bats have babies that cannot fly. To avoid baby bats starving in your attic, do not hire someone to do this exclusion during that time. Most won’t do it anyway. Allowing bats to be successful in raising pups is critical, so even in attics, if there is no immediate human health issue, let the bats remain there until the pups fly, then exclude all the bats. For the homeowner, excluding bats when pups are there runs the risk of dead bats remaining in the attic;

• In barns and outbuildings, tarps or other types of temporary ceilings can be put up to catch bat droppings, and be easily removed for cleaning. Thus the owner gets to use the barn for equipment and the bats get to use it too;

• Building bats houses can help too. Be sure they are large and put up properly (you may need to experiment over several summers). Bats look for good roosting places in buildings, so a bat house should be on a building, near the roof, and on the south side so it can get hot;

Big Brown bats are the most common attic bat and will also use barns and other buildings, both in summer and winter.  At night, after feeding on insects for awhile, they will rest in garages or on porches.  They often have two babies, unlike most of the other cave bats who only have one baby.  Big Brown bats appear to tolerate the drier conditions and somewhat variable temperatures found in buildings, as opposed to the consistent temperatures and high humidity found in caves, so while they will hibernate in caves and mines, they can also use buildings for hibernation.

Little Brown bats also live in houses and barns in the summer, preferring buildings close to open water so they can forage on mosquitoes and other aquatic insects. They hold their single pup between their wings during the day, and prefer to gather in very large colonies, with hundreds if not thousands of other bats around them.  In the winter, they all go to caves and mines.  They are the most susceptible to WNS.

• Tracking bats is important, and Fish and Game biologists want you to tell them about any maternity colonies you have in your houses, barns or other buildings. Instructions for doing a simple count and reporting this are on the bat pages of the NH Fish and Game website.  NH Fish and Game biologists cannot reply to every report, as they get many each week, but they will investigate all new locations with multiple sightings (by phone or by visiting the site).  However, they do use this valuable data, so please send it in!