True frogs - Family Ranidae
This is a group of long-legged, narrow waisted, and smooth-skinned frogs. Adults are typically larger than toads and treefrogs. Their fingers are not webbed, although their toes are joined by webs. The presence of dorsolateral folds aids in the identification of some species.
Males call while floating or sitting in water. Females do not call during the breeding season, but they may give a distress call when captured by a predator.
Many species lay eggs in a film on the surface of the water, while others lay eggs in large clumps attached to vegetation. Tadpoles of true frogs may take two years or more to transform into adults.
In Minnesota most species of true frogs overwinter in well-oxygenated lakes or streams, taking cover among rocks, logs, and leaves.