The thought of having instinctively helpful animals, such as bats, visiting your yard may spark your interest. Perhaps you are concerned of the health risks of doing so. Don't worry, most probably the biggest health risk that humans face from bats is their very own fearful response to them. More individuals hurt themselves in their frantic escapes from bats pouncing for insects (others have even fallen away from docks and boats and nearly drowned!) than they are being harmed by bats. Incidentally, the myth of bats diving into people's hair is the outcome of bats being attracted to the insects that frequently swarm over our heads.
What about rabies? The fact is, bats are the least expected of mammals to transfer the disease; about less than .05 percent of bats get rabies, and rabies is very seldom spread within independent colonies. Rabies is much more likely to hit dogs, skunks, foxes, and raccoons, which establishes any of these creatures a much greater rabies threat compared to a bat. In the rare example in which a bat does bear rabies, even in its rabid state it would rarely be aggressive — unlike any of the earlier mentioned species — and would only snap back in self-defense, once provoked or threatened. In the past 50 years, fewer than twenty-five Americans have gotten rabies from bats. Most individual exposure to affected bats ensues from careless treatment of grounded bats, so just following the "never handle a wild animal using your bare hands" rule of thumb will generally keep you out of harm's way. (Naturally, not all grounded bats are rabid; young pups frequently become grounded when they're trying to learn how to fly.)
Likewise, opposed to what you might have heard, bats are not filthy (the fact is, they clean themselves just like cats) and will not infest the area with dangerous parasites (most bat parasites are so unique that they can not even survive away from their host bats, so they pose low threat to people and other creatures). As for histoplasmosis, an airborne disease induced by a microscopic fungus discovered in bat guano — and that also comes about naturally in soils throughout temperate climates — putting up a bat house far from your dwelling should wipe out any problems resulting from droppings. (Dormant bats do not produce guano, if you have bats that winter over, either inside a bat house or your house.) And apart from being aggressive, bats are really timid and won't attack people or pets.