The calling or singing of frogs is a form of communication. A. For frogs and toads, sound has a number of advantages over visual signals as a medium of communication over long distances at night. B. Calling is performed primarily by male frogs to attract mates for reproduction and to actively compete with other male frogs for females. C. Depending on the species, female frogs can obtain information from a male's song about age, health, and species of the caller. D. In some species both males and females produce mating songs either as individual pairs or as choruses, though the choruses are likely to attract predators. E. Frog calls are difficult to interpret because old frogs and young frogs in cool places produce the same song, and near frogs that are old and weak can sound like fit young frogs calling from a distance. F. Because calling is such a tiring activity for frogs, it is used to communicate only about biologically necessary activities and often in groups that distribute the calling effort among many individuals.