I would really like a bat box, but I don't know how to build one!
Bat Conservation International also has lots of info and plans: http://www.batcon.org/ One of the trickiest things is picking the right place to hang the box. Bats can be picky.
Yes, with a little more research, I've found that you have to but them in really sunny areas. I did end up making one, and I had to paint it black to absorb the most heat. Bats like it really warm apparently!
Hey, that's a nice thing to do. This site will tell you how to build several kinds and also anything else about bats that you need to know.http://www.bats.org.uk/pages/bat_boxes.html FOH
A modicum of searching results in:This hit on instructables andFree plans from the very first hit of google