Tips for Attracting Bats
While research and evidence suggest that bat attractants and lures will NOT attract bats there are a number of factors that WILL certainly help. In fact, one of the biggest attractants are well-designed and well-constructed bat houses. This according to a 12 year long study conducted by the Bat House Project and it's research associates. Research also shows that occupancy is higher in rural areas than urban, 50% of all bat houses had occupancy within the first year and tall, multi-chamber bat houses perform best.
"80 percent of 123 houses with chambers at least 25 inches tall were occupied in 2000."
To understand what attracts bats you first must understand a little about the psyche of them. Bats are wild, free-range animals that area absolute experts at finding homes that are ideal for their young and survival. The primary reason bat attractants don't work, at least long term, is because a bat must find it's home voluntary. This innate instinct is also the reason why they are more attracted to bat houses that stand at least 15 feet off of the ground, usually high-mounted on poles and away from most predators. The extra height also makes the bat house easier for the bat to spot.
Now that you know more about how a bat thinks and have some knowledge of the facts that research has shown let's get into some variables that you do have control over. These are in no particular order of importance, just keep them all in mind when deciding to buy a bat house and nest these friendly guys.
Let these 5 variables serve as your guideline to being a successful bat keeper.
1 - Location
Because bats eat insects, it's only natural that bats usually nest closer to bodies of water, where insects live. It's suggested to locate your bat house be within 1/4 mile of a natural body of water. If this isn't possible then no need to worry, there are plenty of other things you can do to increase your bat house occupancy. An easy one is paying attention to the normal flight pattern of bats in your area and place one there. Also, having a large bird bath, a swimming pool or vegetation nearby would help as well.
2 - Placement
You have a higher likelihood of occupancy if placed on a pole or building, as opposed to a tree. Ideally 15 to 20 feet off the ground and exposed to 6 hours of natural sunlight per day (temperature details below). It's suggested though that they not be exposed to manmade light sources such as streetlights. Also keep in mind that while it may be easiest to mount it to a tree it may make your bats more susceptible to predators (owls, hawks, and even blue jays) who roost within the tree.
3 - Temperature
One of the most critical factors in your bat houses success is the temperature. The ideal temperature for female bats to raise their young is between 80 and 100 degree Fahrenheit. One way you can regulate this is by ensuring that the bat house is placed in a location that will give it at least 6 hours of natural light exposure. This means that cooler climate areas would lend themselves to a southern exposure and warmer climate areas to an east/west exposure. If average July temperatures in your area exceed 85 degree Fahrenheit then it would be best served to purchase a (vented bat house).
4 - Timing
You may mount your box at any time of the year. Bat houses mounted in the spring are often occupied more quickly than those placed at other times. If you are evicting a colony of bats from a building, a box should be mounted several weeks prior to the eviction. Know that bats have strong homing instincts, and once located to a bat house, will attempt to return to their former home. All-in-all, physically placing bats into a bat house is usually for nothing and is not recommended. A good rule of thumb is that if a bat house remains unoccupied after two full years, consider repositioning of modifying the house.
5 - Bat House Construction
While it is not necessary to paint a bat house, doing so can often help in regulating the temperature inside the house. Bat houses in warmer areas, such as the southern United States, may benefit from light colored paint. Cooler areas, such as the northern U. S. and Canada, may benefit from a darker color to help absorb more warmth from the sun. Do not paint inside the house, as the bats need a rough natural surface to hang from when they are roosting during the day.