Bat House
Success
Sun Exposure
Houses where high temperatures in July average
80 F, or less, should receive at least 10 hours of sun; more is better. At least six hours
of direct daily sun are recommended for all bat houses where daily high temperatures in
July average less than 100 F.
Habitat
Most nursery colonies of bats choose roosts
within 1/4 mile of water, preferably a stream, river, or lake. Greatest bat house success
has been achieved in areas of diverse habitat, especially where there is a mixture of
differing agricultural use and natural vegetation. Bat houses are most likely to succeed
in regions where bats are already attempting to live in buildings.
Mounting
Bats find houses mounted on poles or buildings
more than twice as fast as on trees, which are also less preferred. Houses mounted on
metal siding have not been used. Wood or stone buildings with proper solar exposure are
ideal, and locations under the eaves often have been successful. Mounting two bat houses
back to back, 3/4 inch apart on poles, both covered by a tin roof, helps protect from
overheating in hot climates. All bat houses should be mounted at least 10 feet above
ground; 15-20 feet is better. Bat houses should not be lit by bright lights.
Protection from Predators
Houses mounted on sides of buildings or high up
on poles provide the best protection from predators. This may be a key factor in
determining bat choice. Locations at least 20-25 feet from the nearest tree are best.
However, houses may be found more quickly if located along forest or water edges where
bats tend to fly.
Avoiding Uninvited Guests
Wasps can be a problem before bats fully occupy
a house. Use of 3/4-inch roosting spaces reduces wasp use. If nests accumulate, they
should be removed in late winter or early spring before either wasps or bats return.
Open-bottom houses greatly reduce problems with birds, mice, squirrels, or parasites, and
guano does not accumulate inside. Timing
Bat houses can be installed any time of the
year, but are more likely to be used in their first summer if installed before the bats
return in the spring. When using bat houses in conjunction with excluding a colony from a
building, install the bat houses 2-6 weeks before the actual eviction.
Importance of Local
Experimentation
We have much to learn about the needs of
individual bat species in differing climates. It is important to test for local needs
before putting up three to six houses, especially comparing houses of different darkness
and sun exposure. |
