Judy Hawes makes the peeper, one of more than twenty kinds of American tree frogs, an interesting creature to know, and Graham Booth endows him with a very personable sort of homeliness. The peeper, whose chirping song is evidence of spring, is about an inch long, may live for ten to twenty years, and has round sticky discs for climbing at the end of each toe. You might find him more easily on a dark, damp evening, because that is when he sings a lot, and the male's large vocal sac will reflect the light of your flashlight when it is puffed up for singing. An inviting glimpse.