Bat Houses
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Bat House Frequently Asked Questions

 

pallid bats roosts in the rafters
A small colony of pallid bats roosting in a building Credit: Merlin D. Tuttle

I don’t want to build a bat house; where can I buy one?

BCI has certified vendors whose bat houses meet our rigorous standards. You can find a vendor, listed by state here.

 

Should I mount my bat house on a pole or on a building?

Single-chamber bat houses do not work well on poles unless two are mounted back-to-back; better to mount them on a building (south or east sides are usually best). Multi-chambered bat houses can be successfully mounted on either.

 

How high up should I mount my bat house?

Bat houses, whether mounted on a pole or on a building, should be a minimum of 10 feet off the ground, and 12-20 feet is better.

 

Where should I install my bat house?

Do not install your bat house on a tree, which is usually too shady and is vulnerable to predators. Your bat house should be in a sunny place that gets 6-8 hours of sunlight daily, and is 20-25 feet away from the nearest tree branches or other places aerial predators can perch. Your bat house has a better chance of attracting bats if it is near your area’s largest water source, and should also be away from bright lights. Do not install a bat house in an area where you would not want guano to fall or accumulate. 

 

What type of siding should my building have if I am trying to install a bat house?

Wood, Brick, and stone siding work the best. Bat houses mounted on metal siding rarely attract bats. 

 

Will attracting bats to bat houses in my yard increase the likelihood that they will move into my attic or wall spaces?

No. If bats were attracted to your attic or wall spaces and could get into them, they probably would already be living there. The best way to ensure that bats won’t inhabit your home is to keep it in good repair. Bats can enter spaces as small as one-half inch in diameter.

 

I have bats in my house. How do I get them into my bat house, outside?

Attics and other parts of buildings often provide ideal bat-roosting sites. In most cases, bats will not voluntarily move from an attic. In such cases, alternative roosts ideally should be provided several months or one season before the desired move. The bats should be excluded from the attic at a time in the early spring or fall when flightless young are not present. Although it takes a bit of time and effort, exclusion can sometimes be performed by homeowners following our do-it-yourself instructions. Watch to see where the bats emerge at dusk and use exclusion tubes (preferred) or 1⁄6" (4 mm) or smaller plastic mesh to create one-way exits.

 

How many bats can potentially occupy my bat house?

Depending on the size and the number of chambers, your bat house might shelter fewer than 50 to as many as several hundred bats. A very large “community bat house” might attract thousands.

 

How can I determine the likelihood of attracting bats?

Throughout most of the United States and much of Canada, occupied bat houses are being used by one of North America’s many crevice-dwelling bat species. Wherever bats live, they must find enough insects to eat, which largely explains their preference for roosting near aquatic habitats. The closer you live to cave or mine hibernating sites the better, and the existence of bat colonies in nearby buildings and bridges also increases your chances.

 

Pallid bat
Pallid bat, Artrozous pallidus, catches a grasshopper. Credit: Merlin D. Tuttle

How effective are bats at controlling insects?

As primary predators of night-flying insects, bats play a key role in the balance of nature, consuming vast quantities of insects, many of which are costly agricultural and yard pests. Furthermore, many insects avoid areas where they hear bats.

 

Will having bat houses in my yard interfere with attracting birds?

No. They rarely compete for food or space.

 

 

Will bat droppings pose a threat to my family?

No more so than bird or cat droppings would. You should avoid inhalation of dust associated with animal feces of any kind.

 

What are the chances that a sick bat will endanger my family with rabies?

Like most mammals, bats can contract rabies, although very few do. Unlike many other animals, even rabid bats rarely become aggressive. They quickly die from the disease, and outbreaks in their colonies are extremely rare. The odds of being harmed by a rabid bat are remote if

you simply do not attempt to handle bats. Any bat that can be easily caught should be assumed to be sick and left alone. We do not recommend attracting bats to places where curious children are likely to attempt handling them. With or without bats in your yard, the most important action you can take to protect your family from rabies is to vaccinate your family dogs and cats.

 

Are there laws or restrictions in the USA against putting up bat houses?

No, as long as you are putting the bat house on your own land and property there are no laws or restrictions against bat houses. You must obtain permission before attaching a bat house to a utility pole.

 

A baby bat fell out of the bat house. What should I do?

If the bat seems to be injured contact a local, licensed rehabilitation specialist to handle the situation. If it is necessary to handle the pup (baby bat), wear thick work gloves. Try to place the bat on the bat house platform or as close to it as possible. Even place the bat up off the ground and in the tree can be helpful. If able, the mother bat will return for her pup.

 

How many bat houses should I put up?

If you have the space to put up more than one bat house, go for it! The more bat houses you provide for bats, the better. Putting up more than one bat house will also give bats more options and increase your chances of having an occupied bat house. Some bats may prefer one location over the other, or depending on the region and season, they may choose a house in slight shade over a house in full sun.

 

We are moving. What do we do with our bat house?

The best thing to do is to leave the bat house in its current location. The bats rely on that bat house being in its current location and will return to it year after year.

 

How can I protect the bats in the bat house from snakes, cats and other predators?

Our bat houses have a predator guard to keep out most cats and raccoons, however their narrow paws may be able to reach in and grab a bat from a full bat house. Our first recommendation to you is to not put your bat house on a tree. Trees are easy for snakes and cats to climb. Attaching a bat house at least 12 feet high to the side of a building or a metal pole will provide a safer home for the bats.

If you choose to put the bat house on a tree, you can attach metal shield around the trunk of the tree. The metal piece should be around 2 feet wide and be placed high enough so raccoons and cats can’t just simply jump over it, the higher the better, plus it will be out of your way as well. Make sure to place it at least a few feet away from the bat house though, to allow the bats to drop and fly out of the house.

 

Do I have to maintain or clean my bat house?

Bat houses need very little, if any maintenance. On rare occasions wasps may move into the bat house, however if the bats are living in the house with the wasps, there is no need to remove the wasps and disturb the bats. No other maintenance is needed, and it is not common for wasps to move into bat houses.

 

What kind of paint should I use to paint my bat house?

Use an outdoor, nontoxic latex paint for your bat house. The paint should be a water-based paint not an oil-based paint.

 

Will guano (bat poop) build up under the bat house?

If you have a large roost of bats there is a chance that guano might build up just a little, however natural elements such as rain, sun and wind will break down the guano naturally. Bat guano is very high in nitrogen making it a great fertilizer. It is not known to be toxic or harmful to humans, dogs, cats or other animals.

 

Do I need to put guano in my bat house to attract bats?

No, there is no scent or item you can place in or around your bat house to attract bats. The location, temperature and the design are the key factors in bat house occupancy.

 

Can bats be purchased or relocated to my bat house?

It is illegal to buy or sell bats, partially because many bat species in the US are endangered. Also, bats cannot be relocated and introduced into a bat house because they will often return to their original roost.

 

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