Bats eat bugs and feast on them during their night flight feeding frenzy. Mosquitoes are a staple of their diet but so are cucumber beetles, June bugs, stinkbugs and leafhoppers, which are major crop pests. In this day and age of organic farming techniques and awareness of green stewardship, bats help out farmers who desire to practice natural and biological insect control. A colony of 150 big brown bats can protect local farmers from up to 33 million or more rootworms each summer. All crops need fertilizer, and bat guano is processed for organic farming as it is rich in needed nutrients for the plants and soil. Bat droppings contain, approximately 10 percent nitrogen, three percent phosphorus and about one percent potassium in addition to trace elements that can aid in rapid plant growth. It’s also estimated that these nutrients remain in the soil longer than chemical fertilizers that leach out of the soil soon after application.
Bats aren’t just a phenomenon of places like New Mexico and Texas. Washington state is home to fifteen native species, nine of which are on the Washington Department of Fish and Wildlife’s “Species of Special Concern”. Some of the species native to the region include the Big Brown bat; the Silver Haired bat; the Hoary bat; and the Townsend’s Big-eared bat.
Eastern Washington indigenous species include the Pallid bat; Spotted bat; Fringed bat; the Small-footed bat; and the Western Pipistrelle. In all, bats account for twenty-five percent of the total planets mammals. A major area of concern to the public is rabies carried by these winged creatures, but according to the USDA, the number of carriers is far lower than in many other wildlife animals such as raccoons and skunks. Rabies will generally kill a bat quickly so they rarely show the aggressiveness seen in infected canines and felines.
Bats are beneficial to the public at large, and to farmers. One way to insure a good sized colony of these unpaid farm workers is to construct a bat house to attract them. The best-designed houses are 24 to 36 inches tall, 16 to 24 inches wide, and 4 to 5 inches deep. Most houses have 1 to 4 (three-quarter inch wide) roosting chambers. Rough lumber allows bats to cling more easily. Houses should be placed at least 10 feet above the ground, 15 to 20 feet is better. Houses placed on poles or on buildings are preferable to those hung on trees.
Bat houses can be purchased or you can make your own. Books containing plans can be purchased at many bookstores or you can visit the Bat Conservation International, Inc. website www.batcon.org for criteria for successful bat houses and answers to frequently asked bat house questions.