Why do spittlebugs make foam?

Answer: Protection from predators

Trapping prey insects — Wrong. Spittlebugs are herbivores that feed on plant sap, not predators. The foam protects them, not traps prey.

Protection from predators ✓ — Correct! Spittlebug nymphs excrete liquid from feeding on plant sap and blow air bubbles into it, creating foam that looks like spit. This 'spittle' hides them from predators (birds, wasps), maintains moisture, and regulates temperature. It's a brilliant mobile fortress!

Cleaning their bodies — Wrong. Foam isn't for hygiene—it's a protective shelter. The nymph sits inside the bubble mass while feeding, hidden from predators and protected from drying out.