Green Frogs are similar in appearance to Bullfrogs but are smaller
and have two parallel ridges, called dorsolateral folds, on their backs.
They can be green, bronze, olive or brown and are from 2.25 to 3.5 inches long (5.7 to 9 cm). Green frogs are common in permanent streams, rivers, ponds and lakes throughout the Chicago Region. They breed from late April through July. Males make a "glung" noise which is similar to the low string on a banjo; they may also "squawk" as they jump for water when startled. Males defend territories and may have wrestling matches with other males that invade their territory. Females lay massive clumps of several thousand eggs in shallow water. Tadpoles spend a whole year in the water before emerging as frogs. Green Frogs may take up to five years to become adult.