Common Rain Frogs or Ranas de Lluvia Común (Eleutherodactylus fitzingeri) are common in the humid, lowland rainforests and lower montane forests of Costa Rica. During the daytime, Common Rain Frogs will hide under the leaf litter, but at night, these nocturnal frogs will climb onto low vegetation, where the males will start to call. Male Common Rain Frogs will also sometimes start to call during daytime rainstorms as well, which is likely why they are called rain frogs.

I discovered this Common Rain Frog perched on a leaf in the Pacific lowland jungle one evening. This frog was silent, so I don't know if it was a male or a female. A male Common Rain Frog's "chick-chick" calls sound like two pebbles tapping together. You can sometimes get these frogs to reply if you imitate or play a recording of their calls.

Common Rain Frogs are variably patterned, and some individuals possess a pale stripe down the center of the back. These frogs range in color from pale to dark brown, and have a white abdomen, a white stripe on the throat, and yellow spots on the back of the thighs. Unlike Common Rain Frogs, the very similar Eleutherodactylus crassidigitus has a dark eye-line.

Common Rain Frogs lay their eggs in moist spots on the forest floor, and the eggs will hatch into miniature adult frogs, with no free-swimming tadpole stage. Adult Common Rain Frogs feed on insects, spiders, and other invertebrates.