Spring peepers are noisy little frogs. You can hear them calling their mates early in the spring. A fun thing to do is to go out on a warm spring evening after a rain and look for them. Bring a flashlight and continue looking after dark. All you have to do is follow the sound!
See the dark x on its back? This mark will help you distinguish a spring peeper from other frogs.
Spring peeper (Pseudacris crucifer) calling
Learn more about spring peepers at this website from the Maryland Department of Natural Resources: