.Many bats, and almost all in the United States, thrive on an insect diet. A single bat can eat up to 1,200 mosquito-sized insects every hour, and each bat usually eats 6,000 to 8,000 insects each night.Their appetite for mosquitoes certainly makes a backyard more comfortable. Bats are opportunistic, and their lack of discretion benefits everyone. Some of their favorite prey include crop-destroying moths, cucumber beetles, flies and gnats. Natural insect control is their specialty.