As you approach a pond, the sound grows louder, filling the air until you feel almost dizzy. The sounds you hear are not bells, but male northern spring peepers calling for mates. When many peepers sing together, their high, piping whistles blend to sound like sleigh bells. If you had a flashlight, you might be able to spot some of the frogs, but they are only an inch long, and they hide themselves well.
Spring peepers are members of the treefrog family.
Their toes have small, sticky pads that help them climb on low-growing plants. They also cling to grass blades and weed stalks near water's edge. All frog and toad males, regardless of species, have breeding voices they use to attract mates. To make their calls, male toads and frogs close their mouths and noses and force air back and forth from their lungs to their mouths. The air passes over the vocal cords and creates a distinct sound.