How to attract bats to your backyard
Bats are an important part of a functioning ecosystem. Making a bat-friendly place in your backyard supports the ecologically essential role bats have in the environment, including pest-control, pollination and seed dispersal.
Plus, their nightly displays of aerial acrobatics are fascinating to observe.
4 easy ways to be backyard ‘bat friendly’
Install a bat house.
Setting up a bat house near your home is a great way to get involved in protecting bats. Plus, it provides you with the opportunity to observe bats’ fascinating behavior. See below for information on purchasing or building your own bat house.
Don’t tear down that dead tree.
For many bat species, dead trees are like a comfy lodge or beach house – a great hangout spot. Some bats like to squeeze between the narrow, rough space between the tree bark and wood, while others seek out tree hollows to roost. If a dead tree does not pose a safety or property concern, consider leaving it standing.
Don’t use pesticides. (Bats are natural pest controllers.)
Avoid the use of pesticides in your garden and the use of remedial timber treatment agents in structures. Both can lead to the poisoning of bats. Consider bats in your backyard and neighborhood as natural pest control. Insectivorous bats devour astonishing quantities of night-flying insects. In fact, pregnant or nursing mothers of some bat species often consume nearly their body weight in insects each night.
Keep cats indoors.
Cats and bats don’t mix. Period. Cat attacks are one of the most common causes of bat (and bird) casualties. Keep your cat indoors at night, especially during summer months when bat mothers are feeding their young. Make certain your cat is indoors a half hour before sunset and a half hour after sunset when bats are most active. If your cat finds a bat, it may learn where the roost is located, which places an entire colony at risk.
Buy or build a bat house
Where optimal natural environments for bats are limited, installing a bat house is meaningful and a great way to connect to the world of bat conservation. The choice is yours: build or buy?
For-purchase bat houses can be found and purchased online. However, it’s important to know that bat boxes must meet certain criteria to be effective. Use the following criteria to evaluate your purchase:
- A bat house should be at least 24” high x 16” wide. Smaller bat houses do not offer adequate thermal stability.
- A bat house should not contain fabric or mesh. Roosting boards and landing pads should consist of roughened wood.
Bat Conservation International conducted a 10-year study to confirm best practices and provides you with guiding tips on where to locate and install your bat house(s).
Remember, these are guiding tips. You should not be discouraged from installing a bat house if all conditions cannot be met.
Frequently Asked Questions
Where should I place my bat house?
- Bats prefer roosts mounted on buildings or other large wooden or concrete structures rather than roosts mounted on poles or trees.
- Pole mounts can work well in moderate to hot climates that do not experience extreme temperature swings between day and night.
- Tree mounts should be avoided. They are vulnerable to predation and almost always too shaded.
- Bat houses should receive at least six hours of daily sun exposure.
- Bat houses should have a nearby water source, preferably less than a quarter-mile away.
How high? And what about trees?
- The bottom of bat houses should be located 10 feet off the ground. Twelve to 20 feet off the ground is even better.
- Bat houses should have 10-14 feet of clear space above any vegetation below the bat house
- Bat houses should be mounted 20 to 30 feet from the nearest trees.
What about more than one roost?
- Bats are more likely to move into a group of three or more roosts.
- Multiple bat houses can be mounted side-by-side on buildings and structures or mounted back-to-back on poles.
- Some bat house owners number bat houses to identify roosts.
- Some paint north-facing bat houses a light color and south-facing roosts a dark color.
What should I pay attention to when building my bat house?
- Be sure to carefully seal all the seams. Bat houses work best when they effectively trap warm air. It makes the temperatures more stable
- Be sure to roughen the roosting boards and landing pads.
- Avoid using oil-based paints and stains.
If you install it, will they come?
Installing a bat house does not guarantee that bats will roost. Seasonal migration, geographic location, local availability of other roosts, specific roosting behaviors and presence of predators in the area all have an influence on use of bat houses.
If you don’t see bats using your bat house you may be able to find local experts to help you evaluate your placement and construction. Unfortunately, BCI does not have staff to answer specific bat house questions.
Should I mount my bat house on a pole or on a building?
Rocket boxes work only on poles but the 3-4 chambered houses we recommend work best ideally on a building (but can be put on a pole as well). A building offers a more consistent temperature than a pole mount.
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.
I have bats in my house. How do I get them into my bat house, outside?
If you have a colony of bats in your attic or walls, it may be necessary to exclude the bats. Please see a discussion of bat exclusion here: https://www.batcon.org/about-bats/bats-in-homes-buildings/. Though there is no guarantee that excluded bats will move into your bat house, installing one as far in advance of the exclusion as possible will maximize the chance of a positive outcome Bats should only be excluded when bat pups are not present, usually in the early spring or late fall, to avoid trapping flightless young inside.
What color should I paint my bat house?
The color you should paint your bat house doesn’t matter as much as the shade of that color. This varies based on your area and its climate, as the different colors absorb different amounts of heat. Average high temperatures in July should be used when determining the color needed on your bat box:
85 or less: Black
85-95: Dark or medium colors like brown, gray, and green
95-100: Medium/light colors
100 and higher: Light colors or white
What kind of paint should I use to paint my bat house?
Any kind of exterior-grade paint is fine if it’s not oil-based – only use water-based paints. For the inside we recommend 2 coats of water-based stain (do not use paint since it will fill in the grooves).
I want to put up a bat house, but I’m worried about rabies.
We completely understand your concern about rabies and bats. The truth is that any wild mammal can carry rabies (so the squirrels in your yard, raccoons, foxes, rabbits etc.). Bats do not carry or have rabies any more than any other wild mammals. The main thing to remember is that if you see a bat on the ground it’s best to use common sense (like you would with any wild animal). Tell your kids to come get you and not try to touch them or pick them up. If you do pick them up and take them to a rehabber you want to be sure to wear gloves the whole time. The benefits of having a bat house far outweigh the very small risk of having a rabid bat in your yard. They eat lots of bugs (including mosquitos) and are very important for our ecosystem. Bats are losing roost sites everyday due to human disturbances and urbanization, so providing a bat house is a great way to help them!
Why do you no longer recommend the single chamber bat house?
We found the larger houses with more chambers much more successful. That doesn’t mean that a single-chamber house wouldn’t work but we feel that the larger houses provide more meaningful habitat to the bats.