Final answer:
Flea larvae primarily feed on decaying organic material. Insects have diverse feeding habits including being plant-eaters, predators, and parasites.
Step-by-step explanation:
The food of flea larvae is principally decaying organic material. Fleas and lice are parasites that feed on the flesh or blood of larger animals without killing them. Insects have diverse feeding habits, with around half being plant-eaters and others being predators or parasites.