There are Bat Houses of many shapes and sizes but one claims to be the best design, most researched and the most popular with bats. Not all bats will occupy a bat house. Many in the western US will, if the timing is right and other conditions such as design and location are suitable. A bat house provides protection, warmth and a place to roost during the summer.
This bat house was designed and built by the folks at the Organization for Bat Conservation. According to OBC, bat houses placed on tall posts or on buildings work the best. They should have a south-east to south exposure so the house gets nice and warm from the sun. Two or three houses have a better chance of attracting bats. The bats will find your bat house in the spring, after they come out from their winter hibernation. In some warmer climates the bats may use a bat house all year. Bats may prefer to roost in the foliage of trees, under the bark of a dead tree, in tree cavaties left by birds or in a barn or house attic where it is warm and quiet. Below is a plan and some tips for a bat house you can build.
Bat Guano – on the back of my garage.
How do I know there are bats in our yard? Apart from seeing, recording and photographing them, there is a large patch of bat droppings on the back gable of our garage, bat guano. We also have bat droppings on two gables of our house. On the shed roof below the garage gable there is quite an accumulation of guano. I have gathered up some of this for later analysis. At least one bat had roosted there for a time in the spring. There have been no bats observed roosting at these locations. A bat expert has suggested these locations might be temporary night-time roosts.
Plan for a bat house.
Having a bat house in your yard is one way to attract bats. Having two or three is better. After they come out of winter hibernation, bats look for a summer home. If the bats see your bat house, and like it, there is a good chance they will make it their roost. A house like the one shown can accomodate 20 or more bats. There are many bats in Williams but I beleive there are about four that roost nearby our home. They have not moved into my bat house as yet. It has only been up for a short time.
A few tips when building your bat house are:
Make it as natural looking as you can.
Caulk all wood joints above the vent gap to keep the warm air in.
Use glue and galvenized screws for fasteners.
Use 1/8″ rain gutter plastic mesh as a roosting surface, stapled in place.
Attach your bat house to a post at least 15′ high.
Locate it in a flight path area clear of interfering trees, etc.
Face it toward the south or south-east so it will warm in the morning sun.