Larvae mainly feed on invertebrates such as insect larvae and worms. Some bioluminous bacteria infect nematodes that parasitize Lepidoptera larvae. Various larger species of Coccinellidae attack caterpillars and other beetle larvae. Hatchlings mostly feed on invertebrates such as insects, insect larvae, snails, spiders, and worms. Predatory leeches feed on small invertebrates such as snails, earthworms and insect larvae. Tadpoles are eaten by fish, beetles, dragonfly larvae and birds. They are also predators of codling moth larvae. It occasionally eats invertebrates such as insect larvae. Others feed on eggs of other insects, aphids, scale insects, or ant larvae. Some caterpillars, such as the zebra swallowtail butterfly larvae, are cannibalistic. Polyp prey includes plankton such as copepods and fish larvae. The larvae (caterpillars) are also green. The larvae of sawflies are easily mistaken for lepidopteran larvae (caterpillars). "P. interpunctella" larvae (caterpillars) are commonly known as waxworms. These soon hatch into legless white larvae, known as maggots.