Over 40 bat species exist in the United States alone, and nearly 1,000 different species live around the world. They have a bad reputation and are often thought of as flying rats. Although bats are capable of spreading disease, much like rats, their existence is beneficial to humans and the environment in a way rats are not.
While some bat species feed on nectar, other small mammals, fish, or, like the notorious vampire bats of South America, blood, the vast majority of bat species are insectivores and maintain a diet of night-flying insects like mosquitoes, beetles, and moths. As these insects are often pests themselves, controlled populations of bats around homes can be considered favorable.