Higher water temperatures speed up development, and lower temperatures slow it down. Among most species, a tiny, tailed animal known as a tadpole or polliwog hatches from the egg. Kinds of frogs Frogs and toads make up the order Anura, or Salientia, one of the three main groups of amphibians. Most zoologists divide this order into at least 19 families of living frogs and toads. One family of anurans consists of true frogs.
True toads make up another family.
Most true toads have a broader, flatter body and darker, drier skin than do most true frogs. True toads are commonly covered with warts, but true frogs have smooth skin. Unlike most true frogs, the majority of true toads live on land. The adults go to water only to breed. Of the other families in the order Anura, some closely resemble true frogs, and others closely resemble true toads.