Evidence of Spittlebug.

A spittlebug's foamy nest.

There are about 2400 species of spittlebugs or froghoppers worldwide and about 15 in New Zealand
These insects are best known for their nymph stage, which produces a cover of frothed-up plant sap resembling spit. The nymphs are therefore commonly known as spittlebugs or spit bugs, and their froth as cuckoo spit, frog spit or snake spit.

The nymph produces this protective covering in a most remarkable manner by forcing a combination of fluid from the anus and a gluey gland excretion out under pressure, as from a bellows, to make uniform bubbles. The tail pumps up and down to operate the bellows and keep the bubbles coming one every second, and the nymph is soon hidden under a mound of white foam, protected from the sun and from insect predators. The insect can only breath by taking air from one of the larger bubbles or from the air at the surface of the foam. The froth also insulates against heat and cold, thus providing thermal control and also moisture control. Without the froth, the bug would quickly dry up. (- T.E.R:R.A.I.N.)