The froghoppers are a group of Homopteran insects, in the Aphrophoridae, Cercopidae, Cixiidae, Delphacidae, Dictyopharidae, Issidae, Tettigometridae and other related families. They are best known for the larval stage, which produces a protective cover of frothed-up plant sap resembling spit; the larvae are often known as spittlebugs or cuckoo spit. There are many species, a few being serious agricultural pests. The insects pierce plants and suck sap causing more or less damage.