A British Instructional Films presentation.

Cuckoo-spit on grass. Voice over explains that this froth has nothing to do with the cuckoo but with a small insect called a froghopper. C/U of the froghopper. The film follows its life history. Eggs are laid. Tweezers are used to show the place the eggs are laid in grass. The eggs are covered with a hard coating. Froghopper nymph climbs up plant after hatching then it finds an angle in the plant to "blow bubbles to make a home".

Sap is drawn from the stem of the plant then blown out again as bubbles. The froghopper covers itself with bubbles. Extreme close up of the lancet of froghopper compared to a needle. The lancet pierces the stem, the creature sucks in sap and transfers it to bubble blower. Froghopper feeds on the sap and makes more bubbles to repair its home when needed. It leaves cuckoo-spit when it is ready to change from a nymph to a froghopper. It sheds its skin - shown with time lapse photography. Its wings slowly expand. Its power to jump has developed. Cuckoo-spit shown on foxgloves, the froghopper that chooses this plant is different. This type of froghopper changes inside the bubbles rather than on the stem of the plant. We see this process.

End title reads: Revised with the Co-operation of the National Committee for Visual Aids in Education.

Note: this was originally the Secrets of Nature film entitled: "The Frothblower" - see other record. The earlier incarnation may have more images not found in this version.