http://www.batcon.org/home/default.asp
As primary predators of night-flying insects, bats play a vital role in maintaining the balance of nature.
A single little brown bat can catch 1,200 mosquito-sized insects in an hour, and big brown bats are important predators of some of America's most costly crop pests. Cucumber beetles, June beetles, bark beetles, stink bugs, leafhoppers, cutworm moths, corn earworm moths, armyworm moths, termites, assassin bugs, ants, roaches, crickets, and grasshoppers are just some of the many pests known to be consumed by America's bats. Yet, bat populations are in alarming decline due to decades of unwarranted human fear and persecution.
Worldwide, more than 30,000 humans die from rabies each year, and 99 percent of these deaths are due to contact with rabid dogs. In modern countries, where most dogs and cats are now vaccinated against rabies, the disease is rare in humans.
For example, only about one person per year contracts rabies in the U.S. Dog bites remain the most frequent cause for vaccination in North America, but fatalities more often result from contact with wildlife, which is less likely to be reported and treated.
Inexplicably, a strain believed to be associated with the silver-haired bat (Lasionycteris noctivagans), based on monoclonal antibody tests, now accounts for the majority of all North American human rabies cases. How this rare transmission occurs remains a mystery, since silver-haired bats seldom contact people and do not form colonies in buildings or bat houses. Such cases typically cannot be traced to any known exposure.
The good news is that the North American bat species most frequently found in our homes or bat houses, big and little brown bats (Eptesicus fuscus and Myotis lucifugus), are not known to have caused a single case of human rabies in the past 15 years.