Remember the scarecrow in the Wizard of Oz? For a scarecrow, he wasn't really very scary after all, was he? Bats are the same way.

Bats have a reputation for being scary, but they actually do a lot of good--especially for farmers. They love to eat insects, the way you probably love cookies or ice cream. One insect that bats will devour is the corn earworm moth, which costs American corn and cotton growers about $2 billion a year to control and in crop losses.

Agricultural Research Service researchers in College Station, Texas, have been studying whether the great big appetite of one bat--called the Mexican free-tailed bat--includes corn earworm moths. A million of these bats can gobble up nearly 10 tons of insects in just one night. That means the 20 million bats living in Bracken Cave--the most famous of bat "hang-outs"--near San Antonio, Texas, can put a huge dent in moth populations.

ARS meteorologist John K. Westbrook at College Station has studied moth migration--the way moths travel from one location to another--for 17 years. He knows that bats and moths typically fly in the air at about the same altitude.

In early June, billions of corn earworm moths emerge from the Lower Rio Grande Valley along the border of Texas and Mexico. Some moths feed on cotton after feasting on southern corn, while others travel northward to gobble their way through midwestern corn, cotton, and other field crops.

Cotton and corn farmers are controlling the moths mostly by spraying their crops with pesticides. But the ARS researchers are looking for cheaper and more environmentally friendly ways to control the damaging moths. Dr. Westbrook and bat specialist Gary F. McCracken of the University of Tennessee and Merlin Tuttle of Bat Conservation International think that bats could help farmers reduce the numbers of moths chomping on their corn crop and their profits.

In studies to confirm the bats' appetite for moths, Dr. McCracken and Dr. Westbrook attached radiomicrophones to helium-filled balloons called "tetroons." While the tetroons were drifting 2,500 feet above the ground, the microphones picked up the high-frequency sounds of bats searching for and feeding on moths. Now, if more farmers built bat houses instead of bird houses, there might be a big reduction in moths!

Migration refers to:
(a) the movement of moths from place to place
(b) the altitude of 2,500 feet above the ground
(c) the application of microphones to tetroons

To check out other websites for information on bats:
http://www.batcon.org
http://www.lhs.berkeley.edu/BatQuiz.html

--By Linda McGraw, formerly Agricultural Research Service, Information Staff