Bats are one of the best predators of mosquitoes and other night-flying insects. Bat Conservation International (BCI) has some good information about bats in general, put I will link you to their fact sheets on bat houses and attracting bats.

There are also a great deal of information on bats on the internet, found quickly through google or other search engine.

Here is a link that might be useful: Click here for BCI

I have friends who live in a swampy place where the fishing is great. Lots of people have fish camps there. Friend is always telling me about desparate attempts to run the bats out of their garages, crawl-spaces, and "attics". I told her they eat tons of mosquitoes. She said "We don't have any problem with mosquitoes here." Their kids play outside in the dark in the summer. Can't get through to some people.