I've never tried this, because I'm not an evil bastard, and I think bats are cool for the role they play in keeping insect populations down, but I have it on good authority that it's easy to catch bats if you put some rocks in a really furry sock and throw it up when a bat is close by. If you throw something close to a bat they swoop at it to see if it's food, and apparently they get their claws stuck in the furry sock which falls to the ground and you just walk up and collect your bat. Use this knowledge only for good.