Myotis lucifugus

Eats thousands of mosquitoes every night, which makes it a hero. Never pick up a bat lying on the ground.
A bat that lets you get close is probably sick. A healthy one wants nothing to do with you.
Treat it with respect, keep your distance, and tell a grown-up if you see one up close.
Always ask a grown-up before you touch any animal or plant. If something bites or stings you, tell an adult right away.
Source: our source list
Read more about the little brown bat at Wikipedia.