How to Get Rid of Bats in a House

Bats are incredibly beneficial to a balanced ecosystem, but you also want to know how to get rid of bats if they're roosting inside your home. Bats are not inherently destructive, but their waste is high in uric acid which makes it corrosive; it is also incredibly stinky, especially when it piles up on absorbent interior insulation. When large amounts of corrosive bat waste pile up over time, it can compromise a variety of materials and structures.

Learn more about bats and how to get them out of your house; there's only one effective way to do it—through a process called exclusion.

What Do Bats Look Like?

If you can catch a glimpse of them, bats have noticeably scalloped wings and an incredibly distinct way of flying. They are most active at dusk, which can make them difficult to see outside, especially because of their dark coloring. Outside, they are most easily detected by the sounds they make.

There are more than 1,400 bat species worldwide and more than 40 species of bats throughout the United States. When it comes to bats living inside structures, if you live in the U.S. your bat is likely one of three species:

1. The big brown bat (Eptesicus fuscus)
2. The little brown bat (Myotis lucifugus)
3. The Mexican free-tailed bat (Tadarida brasiliensis)

What Attracts Bats Indoors

Your home and yard may be attracting bats. Consider the following:

• Heat sources: Bats like warm nests and they will follow the slightest hint of heat escaping from your home's tiny cracks and holes, then enter the area to nest.
• Water sources: Do you have a fountain, pond, or regularly timed irrigation system that is providing the bats with water?
• Food sources: Are insects (bat food) being attracted to your home because of standing water or exterior lighting at night?
• Harborage areas: Are there plenty of places on your property, such as rock caves and entry to indoor spaces where bats to find shelter during the day?

Signs of Bats in a House

If you happen to have a bat flying around your living space all of a sudden, quickly open the doors and windows to help direct the bat outside. The bat is likely young and did not mean to enter your living space. It just wants to make its way outdoors, where it will spend its time hunting nuisance insects such as mosquitoes.

If you suspect bats are roosting (hanging out) in your home, there are many hints to look for. Keep your eyes and ears open for the following:

• Visual confirmation of bats leaving your house at dusk (typically from the eaves, roof, or attic)
• Interior sounds such as scratching or squeaking inside the attic space
• Exterior sounds, particularly small, high-pitched chirping sounds right around sunset
• Accumulation of droppings inside and outside, especially underneath suspected hang-out spots
• Stains and a distinctly strong odor inside, especially in and around attic insulation

Many signs of bat activity are similar to those of other pests such as rodents, birds, and other wildlife. Unless you see the pest itself, a thorough inspection will likely be needed to confirm which pest you are dealing with.

How to Get Rid of Bats in a House

Bats are an important part of our environment. They are especially good at controlling unmanageable exterior insect issues. A recent study shows that the number of mosquitoes consumed by bats is even higher than what was once thought.

When at all possible, it is encouraged that homeowners find ways to live peacefully with bats unless they are in your house and you need to get them out so their droppings do not cause problems. There is only one truly effective, safe, and humane way to remove bats from your house—you must evict them using an exclusion method. Here's how to begin:

Inspect for Bats Around Your House

Sit outside your home right around dusk and listen for the classic, high-pitched squeaking noise bats make while using their echo-location to hunt. If bats are around, you can often see them swooping around in the twilight while they seek out insects. Watch for them leaving from your roof, attic, or eaves. If you see bats leaving your house and you are confident in your abilities, you can perform a thorough inspection of the site.

If you're going to attempt your own bat inspection, make sure you're prepared for what it will entail. Do not attempt this on your own if you are unwilling to climb a ladder or inspect a potential bat roosting area. To perform a bat inspection, you will need:

• Proper PPE
• A good quality headlamp or flashlight that clips to a hat, leaving your hands free for climbing
• A ladder

Try Natural Deterrents

Bats are very sensitive to smells, so try using natural deterrents first before exclusion, though this may not always work. Use peppermint, cinnamon, or eucalyptus essential oils to deter bats from staying in your home. Combine the essential oil of your choice with water and heavily spray the area where the bats are nesting.

Bats also do not like bright lights or items that reflect light, like foil or mylar balloons. They also dislike noise from wind chimes, which could potentially deter them from coming back to the roosting spot.

Use the Exclusion Method

If natural deterrents do not get rid of the bats, it's time for the exclusion method. Installing a type of "one-way door," also called the exclusion method, is a tool that allows the bat to easily leave the roost but blocks it from re-entering. However, if an entry point is sealed up with a bat or other animal inside and it cannot get out, the animal is likely to die inside, causing a serious smell issue. While this smell should go away on its own in about one to two weeks, exclusion done the correct way helps prevent this issue.

You can make exclusions using materials such as screening, thick, black garbage bags, or specialty tubes designed for this purpose. Locate the bat entry point and wait until the bat leaves to hunt at night. However, if you see one bat, there are likely many more, since they live in colonies.

Once the bat is gone, cover the entry point with the material but help it jut out just a bit so any other bats in the nest feel free to leave. When the bat returns, it will attempt to use its sonar to enter its roosting area in your attic but will no longer be able to detect the open hole or fly back up to reach the hole. This bats will be forced to look elsewhere for shelter.

Seal Entry Points

After you have removed the bats from your attic space or another area through natural deterrents or the exclusion method, you will need to seal it up. Let the bats leave before sealing the hole, as this will make sure they don't die inside.

Perform an interior attic inspection as well as an exterior roof inspection to determine all the holes that need to be closed up where the bats entered to get to their roosting spots. Make sure all vents, flashing, and the areas around your chimney are sealed. Look around the entrance of the holes for greasy residue and discoloration, also called 'grease trails so you can make sure you have closed up all the possible entry points.

Avoid Bat Repellents

There are a number of bat repellents on the market including essential oil pouches and ultrasonic devices. Repellent solutions can be hit or miss. Know that these solutions can involve a lot of work and money with varied results. When possible, it is recommended that you keep the bats around and focus primarily on sealing them out of interior spaces, not using repellents.

How to Prevent Bats in a House

If you see bats around the outside of your house, you want to find the best ways to keep them outdoors where they should be so they don't want to enter your home.

Reduce Exterior Sources

Reduce exterior food and water sources that are very close to your home. Bats love to eat insects. Make sure your exterior lights are off at night to help reduce the surrounding insect population and bat activity. Bats are also attracted to bird nectar feeders and standing water they can use to get a drink. Reduce these attractants, and you will reduce the chances of a bat accidently finding its way into your home.

Hang a Batbox

There's no denying how beneficial bats can be, especially when it comes to reducing insects such as mosquitoes. It may seem contrary to your goal of getting rid of bats, but once you seal the bats out of your attic space, consider purchasing or building a bat box (or five!) for your bat friends. You can reap the benefits of a smaller nuisance insect population and the surrounding bats will be less likely to try and enter your home when they have such a favorable spot available to them.

When to Call a Professional to Treat a Bat Infestation

If you are dealing with a severe bat infestation issue, call a professional IPM specialist, especially if extensive clean-up is needed. A pro can also help if you are wary of heights or creepy critters and they can handle all aspects of the exclusion process.