Ivriniel's Profile

Bats eating 600 mosquitoes an hour is a myth. The number was arrived at, after someone observed a bat eating for 15 minutes, shot it, analyzed its stomach contents and multiplied by 4.

A much better study of the feeding habits of bats was undertaken by a Graduate student (whose name escapes me at the moment) working under Prof. Brock Fenton. She examined bat guano for insect remains on a covered bridge in Pennsylvania, and found that they ate very few mosquitos, preferring to focus on larger prey.

That being said, building a bat house is a great idea. People should do it because bats are cool and are under threat due to habitat loss, not because they think it will make the mosquitos go away.