Through the efforts of conservation organizations, many people have learned of the benefits of having bats near their homes. These gentle mammals are predators of night-flying insects such as moths, mosquitoes, cucumber beetles, June beetles, and leafhoppers.

Although bats have relatively good eyesight, they depend primarily on a well-developed echolocation system similar to sonar. Bats emit pulses of very high frequency sound, which are inaudible to humans, at a rate of a few to more than 500 per second. By listening to the echoes that reflect back to them, bats are able to maneuver around objects in their path and capture tiny flying insects.

Bats generally mate in fall and delay fertilization until spring, when the female usually gives birth to one offspring. Red bats, a tree-dwelling species commonly seen in urban areas, may produce twins or even quadruplets.

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Courtney Celley/USFWS

More than 20 bat species have been documented in Oklahoma, several of which are migratory and leave the region for the winter. Seven bat species are more likely to occupy bat houses in both urban and rural areas. In general, any species that naturally roosts in buildings, under bridges, or in tree cavities is a bat house candidate.

• Little brown bats are found throughout eastern Kansas and Oklahoma; males might use houses for summer roosts.
• Cave myotis are found in New Mexico, southern Colorado, southwest Kansas, and western Oklahoma and Texas. They probably would use houses for late summer and early fall roosts.
• Pallid bat also are found in New Mexico, southern Colorado, southwest Kansas, and western Oklahoma and Texas. They probably would use houses for summer roosts.
• Mexican free-tailed bats migrate each fall to Central and South America but return in spring to set up nursery colonies in gypsum and limestone caves in New Mexico, Colorado, southwest Kansas, Oklahoma, and Texas. Large houses could be used to rear young, although houses are more likely to be used by bachelor colonies or as roosts by transients
• Tricolored and evening bats are found in Missouri, Arkansas, Louisiana, and eastern Kansas, Oklahoma and Texas. Both bat species probably would use houses for rearing young and for summer roosts.
• Big brown bats are widespread throughout the United States and use houses for nursery colonies or summer roosts.

Although most bats live in caves or in trees, some can be attracted into bat houses. A successful bat house depends upon many factors, but biologists have found that variety is the key. The more variety you can provide for the bats, the better the chance of attracting them. In general, a successful bat house should:

1. Be located a quarter mile or less from a stream, river, lake, or standing pond.
2. Receive six to eight hours of daily sun. For best results, face the house toward the south, southwest, or west.
3. Be painted light brown to absorb additional heat. Caulk all seams, especially around the roof, before painting. Apply two coats of exterior latex paint to all outer surfaces and entry areas. Do not paint or stain inside the house.
4. Contain a ½-inch horizontal vent across the front of the bat house and about 5 inches from the bottom. This vent prevents the bats from overheating and may also assist bats in locating the house.
5. Be mounted at least 15 feet above ground. Houses mounted on the sides of buildings or on poles are twice as attractive to bats as houses placed on trees. Bat houses placed under the eaves of wood or stone buildings are especially successful when exposed to the sun.
6. Be erected in groups of three or more, offering more variety of temperatures. Houses on the sides of buildings should be placed close together but at different heights. Pole-mounted houses should be placed back-to-back, ¾ of an inch apart, and covered by a tin roof. They should have a north-south orientation for maximum temperature gradients.

If bats don’t occupy houses after two summers, experiment! Bat roosting preferences are still not completely understood. Try moving the house a fewer feet to receive more or less sun, try raising it higher off the ground, or paint the house a darker or lighter color. Double check your assessment of the house’s location. Have all criteria for bat house placement been met? Generally, do not expect bats to use your house during winter. Other management recommendations include:

• If wasps become a problem in your bat house, blast them with a high-pressure hose. Scrape mud dauber nests early in the season for better control. Do not use pesticides!
• Check bat houses for bats once or twice a month in summer and then once each fall and winter. After bats are established, check only a few times per season. To check bat houses, briefly shine a flashlight into the house, being careful not to touch the house and being as quiet as possible. Another way to check the house is by watching it at dusk or dawn and seeing if any bats fly into or out of the house. Also, look for bat droppings under the house.
• If the wood of your bat houses begins to warp, especially near the top, seal any gaps with silicon caulking. If the warping is significant, build a new house. Drafts keep bats from trapping body heat efficiently and from maintaining optimum conditions for rearing young.
• Besides mounting bat houses, you might consider loosely wrapping corrugated metal around tree trunks to provide protection from predators.