The life cycle of the cockroach includes three stages: egg, nymph and adult. These same three stages are common to insects that do not undergo metamorphosis. While temperature, species and factors from its environment affect the lifetime of the cockroach, German cockroaches complete their life cycle in about 100 days, according to the University of Florida.
Cockroach reproduction requires the female to produce an egg, which the male fertilizes. Most species of cockroaches lay their eggs to develop outside the body, but a few keep the eggs inside and give live birth.
Nymphs exit the egg looking much like the adult insect but do not have wings. As the nymph grows, it molts, leaving its outer shell behind. Most nymphs molt approximately six times in the 60 days between hatching from the egg and becoming an adult. Newly molted nymphs are pale in color and are sometimes mistaken for albino cockroaches; however, within a few hours, they return to their normal dark brown color.
Once the cockroach reaches adulthood, it is ready to reproduce. With ideal temperatures and nutrition, the number of cockroaches in an area grows exponentially. Cockroaches are pests as they contaminate food with their fecal material. When populations are high, cockroaches bite people or feed from food left on the individual's face as he sleeps.