froth nest

A froth nest is a nest made of froth, typically by certain species of frogs and toads. These nests are created by the male frog or toad, who kicks vigorously with his hind legs while the female exudes eggs. The result is a frothy mixture of water, air, eggs, and semen that floats on the water's surface.1

These meringuelike nests are about 7.5 to 10 cm (3 to 4 inches) in diameter and about 5 cm (2 inches) deep. The outer surfaces exposed to the air harden and form a crust, covering the moist interior where the eggs are randomly distributed. Upon hatching, the tadpoles wriggle down through the decaying froth into the water.1

The term "froth insect" is also used, though less commonly, as a synonym for "spittle insect".2