BATS and BAT HOUSES
Frequently Asked Questions
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Do bats transmit the West Nile Virus?
According to Bat Conservation International, bats are "dead-end hosts" for the West Nile Virus. This means that mosquitoes can infect bats, but bats do not transmit the virus back to mosquitoes. Since the virus is transmitted to people by infected mosquitoes, bats do not transmit the West Nile Virus.

Because bats are huge consumers of insects, bat houses can aid in the control of mosquitoes. Therefore, installing bat houses can help to reduce the threat of West Nile Virus.


How do I exclude bats from my house?
First, find out how the bats are entering and exiting the house. This is done by watching the house at dusk to try to determine where the bats are leaving the building when they go out in search of food. If possible put a piece of netting or screening over the opening. Attach the top of the netting several inches above the opening and along the sides at least a foot to either side of the entrance. The bottom is left open so the bats can drop out. The netting will form a one-way flap so the bats can exit, but they are unable to reenter.

PLEASE NOTE!!!
The timing of exclusion is critical. Since it is important to not abandon babies within the building, it is imperative that the babies are also able to exit before excluding the parents. Most species of bats have their babies after returning from hibernation in the spring, so it is best to limit exclusion to the fall of the year. With this timing, the bats will have already left for hibernation and/or the babies are mature enough to survive on their own.

To relocate the bats, it is best to mount a bat house at the time of exclusion. Hopefully, when the bats cannot reenter the building, the bat house will provide the next best residence. In this case, it is sometimes recommended that a bit of bat guano from the previous residence will indicate familiar surroundings.

Useful links for more information:
Do-it-yourself Bat Exclusion
Professional Excluders

Where should I hang my bat house?
The most successful bat houses are those mounted on a building or a chimney at a height of 15 feet or more. In cooler climates the bat house should be mounted facing the south or east. In warmer climates all directions have proved successful. The house should face a clearing and be located away from branches or power lines. Bat houses with ventilation slots on the side should be mounted so the slots will not be obstructed by the eaves of the building. Pole mounted houses may be more successful if the house is mounted on a backboard measuring one or two feet larger than the bat house (similar to a basketball hoop mounted on a backboard). Plastic mesh or nylon window screen should be securely stapled to the entire backboard to provide a foot hold for the bats landing on the board to enter the house. Bat houses mounted on trees are the least successful because bats that naturally roost in trees are solitary and roost openly on branches (colonial, crevice-dwelling species use bat houses).

How can I attract bats to my house?
There is no known substance or plant that attracts bats or increases the chances of a bat house being occupied. However, bat houses that are mounted within one mile of a water supply are more quickly inhabited than those without a water source. In addition, houses that are located in areas where colonies of bats already exist in buildings or caves are more likely to be occupied.

Can bats be purchased or relocated to my house?
It is not legal to buy and sell bats, in part because over 56% of bat species in the US are endangered or official candidates for listing with the United States Fish and Wildlife Department. Bats cannot be relocated and introduced into a bat house because they are highly territorial and will simply attempt to fly back to where they come from.

Will a bat house interfere with my bird house?
No, birds and bats do not compete for food or space.

Can a bat house on my house be dangerous?
Although bats rarely contract rabies, those that are found on the ground are more likely to be sick (or injured) and may bite in self-defense when handled. Consequently, children should be taught to never handle bats and pets should be vaccinated against rabies. If a bat is found grounded do not handle it with bare hands. Use leather gloves or a thick cloth to gently gather up the bat. Place the bat into a box, affix a lid and call a wildlife rehabilitator or organization for help. Keep the box in a area away from children or pets until help arrives. If the bat has already been handled without gloves or has had (or is suspected of having) contact with children or pets, please call your health department as well as animal control. Bat droppings (guano) pose no more of a health threat than the droppings from birds or other mammals. Potted plants placed under bat houses will receive fertilizer straight from the bats, resulting in beautiful plants!

Will a bat house attract bats to live in my home?
If bats were attracted to your home they would probably already be roosting there.

I already have a bat house and have had no luck, what's wrong?
The house may not be mounted in a good location or the house may be a poor design. Be wary of bat houses that seem small, offer no ventilation and do not have screened or grooved surfaces to provide proper foot holds. If you have already purchased a bat house that you suspect is a poor design, try modifying the house by adding the above recommendations.

How can I tell if bats have found my house?
Colonial bats are often noisy throughout the day as they change roost mates or compete for a favored spot in a roost. Another indication that bats are occupying your house is evidence of bat droppings on the landing platform or on the ground beneath the bat house.

Will predators bother bats living in a bat house?
Bat houses mounted on buildings probably offer the safest location from predators. To prevent animals from climbing, predator guards or tin should be wrapped around poles on which bat houses are mounted.