Bats in Los Angeles County

Are there any bats actually living in Los Angeles County?

The answer may surprise you—LA County is home to a large number of bats of different species! Bats may live in urban and suburban areas, not just the countryside. Most people do not see our local bats, even when they live nearby. Bats sleep during the day, and come out at night to eat insects.

Never touch a bat (video 0:32) (opens in a new tab)

Bats are an important part of the ecosystem and help us by eating insects and pollinating plants. Healthy bats will avoid humans and other animals. On rare occasions, a healthy bat may wander into your home while following insects. Sometimes finding a bat in your home means there are others living in the attic space of your home.

If a bat has rabies, it can spread it to people or pets through bites. Only about 1% of bats in nature have rabies. However, bats that fly during daylight or have encounters with people and pets are more likely to be rabid—in recent years about 10-15% of these bats test positive for rabies in our county. In the peak months of late summer, 1 out of every 3 bats tested is positive for rabies.

Sometimes bats are found inside homes or on the ground in a yard. Encountering a bat may be a startling experience and a potentially dangerous situation, but you can safely handle the situation by following a few simple steps.

Things to remember if you encounter a bat:

1. Stay calm. The bat’s intentions are not to harm you, but it will bite in self-defense.
2. Isolate the bat. Make sure no pets or people are near the bat.
3. DO NOT TOUCH THE BAT (or any other wildlife) with your bare hands. Wear thick gloves when you approach the animal, since an infected bat can transmit rabies through biting.
4. It is illegal to keep, injure, or kill bats. Please do not attempt to rehabilitate the bat on your own or harm any bats when trying to exclude them from your house. If you find a bat in your home or on the ground, contain it and call Animal Control and ask them to collect it for rabies testing.

If you see a bat on the ground, do not touch it with bare hands.

Keep people and pets away from it.

If the bat is moving and appears healthy, leave it alone. If the bat is active during daylight hours, it will most likely be disoriented and may be sick. If it appears sick and shows little movement, contact your local animal control agency (opens in a new tab) and gently cover the bat with a container with air holes until they arrive. Make sure no one touches the bat.

If someone has touched or been bitten by the bat, the situation must be treated as a potential rabies exposure. You will need to submit the bat for rabies testing. Simply place a box over the animal and contact public health at 213-288-7060 as well as your local animal control agency (opens in a new tab).

If you have additional concerns about identifying a potential rabies exposure or advice on capturing the bat, please go to the Bats in the House section.

Bats sometimes roost inside attics, walls, or other parts of buildings.

If there are multiple bats inhabiting your attic or another room in your house, the best course of action is installing a one-way excluder device—a “door” that allows bats to fly out but prevents them from returning inside. This also involves “bat-proofing” your home and sealing off other potential entrances.

It is important to avoid performing exclusion procedures in the summer months (May-August) due to the baby bats that may be inside—with the exclusion device, they will be unable to obtain food and will die. Remember to be mindful of the season when preparing for bat exclusion and do not trap bats inside. Remember that it is illegal to kill bats roosting in your home.

After all the bats have disappeared, safely dispose of the guano (droppings) that they may have left behind. The droppings may not only leave a strong odor but also possibly grow mold and transmit disease, so it is best to consult a trained professional and safely eliminate the guano.

For detailed information about bat exclusion, please visit UC Statewide Integrated Pest Management Program - Bats (opens in a new tab).

Are you considering building a bat house?

Bats are a very important part of our local ecosystem. Bat houses can provide protection and habitat for them. However, there are health issues to consider when choosing the location for a bat house.

When wild animals are invited into areas close to your home, there is an increased possibility of a person or pet coming in direct contact with wild animals. Before adding a bat house to your yard or garden, the following should be considered.

1. Is your home “bat proof”?

Bat houses can provide a nice roosting area for bats, but often attic or rafter space is even more hospitable. Therefore, search your home for any openings ¼ inch by ½ inch or larger (to include electrical and plumping holes) and apply caulking. Ensure all doors to the outside close tightly. Always use window screens, chimney caps and draft-guards beneath attic doors.

Avoid “bat-proofing” your home from May through August when young bats can get trapped and die. During fall and winter when bats hibernate is the best time to “bat-proof”.

Additionally, bat houses shouldn’t be mounted directly on homes as it can increase the chance that a bat may fly into the home through an open window or door.

2. How close are your neighbors?

Even if you “bat-proof” your home, your neighbors may not and your bat house could increase your neighbor’s chance of encountering an unwanted bat.

Are children or pets nearby?

Children and pets are curious by nature and may attempt to handle a bat on the ground. Therefore, bat houses should not be installed in areas easily accessible to children and pets.

3. Have you read all about bats and rabies in LA County?

It is vital to educate yourself and your family about bats and rabies in our county before building a bat house. Learn about rabies in LA County, including the latest rabid bat statistics.

The two most common diseases associated with bats in the United States are rabies and histoplasmosis.

Rabies

Rabies is a fatal disease caused by the rabies virus. People can become infected when bitten by an infected bat, or when saliva of an infected bat comes in contact with the eyes, nose, mouth or an open wound. Any bat that bites or has possible contact with a person or pet should be tested for rabies. Call your local animal control for assistance. Learn how to safely capture and contain the bat (PDF, opens in a new tab).

Bat bites are very small. Some bat bites cause only minor pain. A wound from a bat bite can easily go unnoticed. Therefore if there is the possibility of contact with a bat, a physician or the Department of Public Health should be consulted to evaluate the risk of rabies. Any suspected bite should be washed with soap and water immediately and prompt medical attention sought. If there is a possibility that your pet came in contact with a bat, a veterinarian or Veterinary Public Health should be consulted to evaluate the risk of rabies.

If a person was likely exposed to the rabies virus, symptoms can be prevented with a series of rabies vaccinations given in the upper arm over a few weeks, as well as rabies immune globulin (antibodies) given at the beginning of the treatment. This is called ‘rabies post-exposure prophylaxis’ or rabies PEP. Because rabies is such a serious disease, rabies PEP is needed after any bat bite unless the bat tests negative for rabies. If it is needed after a bat incident, rabies PEP should be started as soon as possible (i.e within 1-3 days). Symptoms of rabies from bats usually start 30-90 days after the bite. If symptoms occur, the disease is nearly always fatal. For additional information on rabies in people, visit CDC: Rabies (opens in a new tab).

If a pet was likely exposed to the rabies virus, they will be either quarantined for 30 days if vaccinated for rabies or for 6 months if not. Additionally, a series of rabies vaccines would be recommended to help prevent disease. Signs of rabies usually start 3-8 weeks after the bite. If signs of rabies occur, the disease is fatal.

Histoplasmosis (opens in a new tab)

Histoplasmosis is a disease caused by the fungus Histoplasma capsulatum. It can be anywhere there is a large amount of bat droppings (guano). People can become infected if they breathe in the fungal spores. Symptoms are similar to pneumonia (including trouble breathing and coughing) and should be treated early to avoid severe disease. The risk of contracting histoplasmosis from bat guano is no different from the risk associated with bird droppings. Professional services should be sought to clean up areas with large amounts of droppings.