Bats are nature's most effective controllers of flying insect populations. For example, the big brown bat?common throughout the United States?can consume up to 1,200 mosquitoes an hour. Unfortunately, most of the 46 bat species that live in the United States and Canada have experienced serious population declines over the past half century, and six are considered endangered. Here are some ways you can protect bats, and have them control mosquitoes in your back yard.

1. Avoid caves and abandoned mines.

The primary cause of bats' decline is the loss of hibernacula, places in which bats can hibernate without human disturbance. If you know of a cave or abandoned mine where bats live, stay away from it?particularly during late summer through spring?and report its presence to wildlife officials for possible protection.

2. Turn off bug zappers.

The biting insects that zappers supposedly control actually aren't attracted to light. Instead, moths and other insects on bats' diets are the zappers' victims. Bats terminate mosquitoes and other pest insects much more efficiently, and bats are far more likely to be attracted to your yard if there are moths.

3. Put up bat houses.

About a dozen bat species are attracted to well-designed bat houses. Such houses provide critical shelter, particularly in the spring and summer when mother bats need safe places to raise their young. Use a properly constructed bat house and install the house at least 10 feet above the ground in a place that will receive the right amount of solar exposure for your region. You'll find more information on bat houses, and plans for building your own, from the following bat groups:

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• Bat Conservation International
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• Bat Conservation and Management
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• Organization for Bat Conservation
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To read more about these amazing creatures, check out Terry Krautwurst's story, 'Fantastic Bats,' in the October/November 2005 issue of Mother Earth News.