The larvae of a cockroach are known as nymphs. Option 1, caterpillar, is incorrect as caterpillars are the larvae of butterflies and moths. Option 3, maggot, is also incorrect as maggots are the larvae of flies. Option 4, grub, is incorrect as grubs are the larvae of beetles. The correct term for the cockroach larvae is nymph, which goes through multiple stages of growth before reaching adulthood. The nymphs look similar to adult cockroaches but lack wings and are smaller in size.