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.
Bat House Tips
- 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.