Deserts aren't usually considered rich in amphibians, and yet twelve species are found in Big Bend National Park. Along the banks of the Rio Grande, Leopard Frogs grunt and chuckle and the high trill of the spotted toad may be heard on warm summer nights near springs and moist areas.Big Bend's most intruiging amphibian is the Spadefoot Toad. Named after the hard "spade" on each hind foot, the spadefoot lives in the hot areas of the park. The majority of its life, this toad is deep underground sealed in a gelatinous slime coat to hold in body moisture. When they hear summer rainstorms on the surface above, spadefoots frantically dig out to find tiny pools of collected rainwater. They quickly sing to attract others. Mating takes place, eggs are laid, and tadpoles develop to adults within two weeks—hopefully before the pools dry up.