Giant Bats And Bird Houses Solve Insect Problems

When it comes to insect control, you can't beat what a thriving colony of bats can do. An individual bat can eat thousands of insects in one night. "They'll usually eat about a third of their weight or more in flying insects every night," says Mark Hostetler, a University of Florida-Gainesville extension wildlife specialist. A bat house built in 1991 on that campus now houses over 100,000 bats which eat vast quantities of insects in and around campus.

Hostetler says they eat just about any insect that flies -- including flies. But for crop farmers, it's good to know they also eat moths, including the moths that are the adult forms of armyworm, corn earworm and cutworm. They also eat leafhoppers of all varieties and some bat species, particularly big brown bats, eat larger insects like cucumber beetles and stinkbugs.

Hostetler says there are a lot of ways to attract bats.

While bats go after most flying insects, mosquitoes are usually a small portion of their diet, Hostetler says.

If mosquitoes are your main concern, you might want to encourage another prolific insect eater -- purple martins.

John Carson, owner of Big Island Ranch Ltd., Sherwood Park, Alta., says problems with mosquitoes on his farm have been significantly reduced since he put up a couple of giant purple martin houses. Those two houses can each provide shelter and nesting for 112 martins, and he has a smaller 16-hole house on a pole near his home.

"Before we put up the two big houses, we used insecticide sprays to control the mosquito population," he says. "We haven't had to spray here in four or five years." The reason is that purple martins eat their weight in mosquitoes and other insects every day.

Carson's large houses are mounted about 15 ft. off the ground on posts above the gates between the pastures where his elk herd grazes in the summer.

He had the large houses built by a local retiree who likes to do wood working. "We had put up some metal houses along with some small wooden ones and the martins always filled up the wood before they'd move into the metal ones," he says. "So we decided to have the big ones made from wood."

He says attracting purple martins is easy. "We started with a small house and then just added to it when they'd gotten used to coming here," he says.

He suggests starting with a 16-hole house. It's important that the house be located in an open area, not around trees, and that it be about 15 ft. off the ground.

"They're very clean birds. There's never any droppings around their house, like you'll see with many other birds," he says.