Coexistence

Bats as neighbors

Why are bats important? 

Bats are critical to the ecosystems they live in. Here in the Pacific Northwest they consume so many insects that, if they suddenly disappeared, it would cost billions of dollars in pesticides to do the same job. But the result would be massive amounts of poison added to our environment. Bats are the major predator of night-flying insects. These insects include many that are pest species to us, to our gardens, and to the agriculture and forestry industries.

Do bats live in the city?

Absolutely! Bats find roosts in attics, hollow trees, bridges, parking garages, out buildings and other such structures. Hunting can be very good in the city because lights attract insects, while lakes and ponds in parks provide water and additional foraging areas.   

Are bats good for my garden?

Our bats eat many insects that normally feed on plants such as moths, flies and beetles. Additionally, their droppings, or "guano" is one of the world's best fertilizers. Bats are part of a healthy ecosystem.

Can I attract bats to my house?

Bats are wild animals, with minds of their own, so there are no guarantees. But there are things you can do to create a good "bat environment". Visit our bat habitat page to learn more.

Bats in Buildings

Is there just one bat? (If there are many bats, keep reading below!)

One bat can be carefully removed from your home. You can encourage the bat to leave in the evening by turning off all the lights in the room and opening all doors or windows to the outside; stand in a corner of the room against the wall and watch to make sure the bat flies out. If this doesn’t work, it is possible to carefully capture and release the bat. You can watch this video from Idaho Fish & Game to learn how or visit our Found a Bat page.

How can I tell if the droppings I find are from bats or mice?

Even though they are similar in size and appearance, bat and mouse droppings are different due to their different diets. Mice eat a lot of plant material and their droppings don’t crumble when pinched. Bats eat insects so their droppings contain tiny bits of insect exoskeletons and thus are sparkly in the sunshine and crumbly in texture.

How are the bats getting in?

Washington bats are quite small, and can squeeze through an one inch opening. Attics and walls provide good roost sites, and bats often can enter areas where the sides of a house meet the roof or chimney. If bats have been using an entry for any length of time, it becomes stained and easier to identify. You can also find entries by watching the area before and during sunset to see where bats emerge.

Unlike rodents, bats do not make nests nor can they gnaw, so they do not physically harm your home. If they roost in a home long enough large amounts of strong-smelling guano or urine can build up. Use the resources below to safely and humanely exclude bats from living in your buildings. 

Can I get rid of bats in my attic with light? With noise? With garlic? With moth balls?

Unfortunately the answers are “no”, “no”, “no” and “no”. Bats living in attics are usually maternity colonies. The moms may put up with just about anything to keep a good roost and protect their babies, including noise, light, and strong smells. In some places, bats are able to put up with smells so strong that humans must wear protective masks. Moth balls are also a bad choice because they have been found to be a carcinogen and dangerous to the people living in the house.

How do I get rid of the bats living in my attic?

The best and safest - for both the bats and the humans - way to remove bats is to exclude them. In the Washington area, this must NOT be done during May, June, July or August because these months are when babies are born and still unable to fly. Read our Excluding Bats From Your Home section below.

If I put up a bat house, will the bats leave my attic?

Unfortunately, no. Bats are extremely faithful to a preferred roost and attics are usually much warmer, quieter, safer and larger than a bat house. But putting up a bat house before an exclusion is being done can help. When the bats are left homeless, they will have a new place to go and you will keep them in the neighborhood eating your bugs!

Visit our Bat House Central for more information on building and installing bat houses. 

Visit Bat Conservation International’s Bats in Buildings web page for more information.

Excluding bats from your home

Excluding bats from your home is not difficult. Even though bats are a vital part of the ecosystem, there is no reason you need to allow them to live in your home.

They can be excluded from your dwelling by following these recommendations:

  • Perform exclusions only in late August or later, after the pups have been weaned and are able to leave the roost on their own. You do not want to seal young animals inside a structure where they would die and lead to further problems for you.

  • Identify the entries the bats are using. Find them by looking for stained places on the sides of your house and watching in the evening for the bats to emerge. If there are many entries to the same roost, seal all but one.

  • During the day while the bats are asleep in their roosts, create a one-way flap-valve by positioning netting (1/4″ mesh or less) hanging loosely in front of the exit. (Nylon netting can be purchased by the foot in stores such as Home Depot.) Tape or tack the top and sides, but leave the bottom open with the netting hanging loosely down a foot below the entry. The bats will be able to leave, but not reenter.

  • When the bats emerge, they will meet the netting and start climbing around trying to find a way out. Soon they will get out the bottom and go off to eat. But they are not clever enough to get back in the same way in the morning. You have created a “one-way door”.

  • Leave the netting up for 2-3 nights to make sure all the bats are out.

  • After a few days, take the netting down and seal the holes. This is very important because the bats will return if they can! Any caulking can be used since, unlike rodents, bats do not gnaw holes, shred materials, build nests or cause structural damage to buildings.

  • Think about providing an alternate home for these bats. Bat houses mounted close to the old entry are usually used quickly.

Further information and assistance

  • Nuisance Wildlife Control Operators These professionals are trained and regulated by Washington Department of Fish and Wildlife to provide assistance with nuisance wildlife and normally charge a fee for their services.

  • Live in SW Washington? For professional help excluding bats contact Wayfair.

What you need to know about bats, disease, and your health.

Bats and Your Health

Rabies

The most common public health concern with bats is rabies, a neurotropic virus spread by animal bites that causes brain inflammation and death. Very few bats in healthy populations have rabies and bats are not "carriers" of rabies - spreading the disease without being harmed themselves. All mammals contract rabies when bitten by another infected animal. Studies indicate that about 1/10th of one percent of a wild bat population may be infected with the disease.

Rabies is not something to take chances with. Wild animals should not be approached or touched. Whenever an animal is acting strangely, it should be avoided. If a wild animal allows you to approach it, something is wrong. Bats should never be handled without protection from bites. Any possible exposure should be discussed with your personal physician immediately. Post exposure shots can be given to protect a person from developing the disease if they are administered before the symptoms of rabies appear.

Histoplasmosis

Histoplasmosis are fungal spores which are usually inhaled from aerosolized bird or bat droppings in a closed space and cause respiratory symptoms similar to those of the flu or pneumonia.  The fungus is only found in certain areas of the United States and is not as big a concern for public health as rabies.  The primary areas where the fungus occurs are the Ohio, Mississippi and Rio Grande River valleys, the Southeastern states and the Central Valley of California.  The fungus is not considered a public health threat in Washington state.

Teach children not to approach or handle any wildlife, and keep pets up to date on rabies vaccines to keep yourselves and our wildlife safe!

  • Learn about shots to prevent rabies.

  • Read the Washington State Department of Health Fact Sheet on Rabies.

  • Contact your local Health Department with concerns.

Being near wild bats does not expose you to risk. Having bat houses nearby, observing bats flying overhead, or living near a known roost will not endanger you or your family.