There are 3 distinct stages to the life cycle of cockroaches. The first stage is the egg stage. Mother cockroaches carry up to 40 eggs around in a sac on her abdomen called an ootheca. Some species will carry this ootheca within their bodies instead of externally. After 6 to 8 weeks small cockroaches emerge from the sacs, starting the second phase - the nymph phase. Nymph cockroaches, which are smaller adolescents, grow into their adult size over a year. Even small amounts of food can sustain these pests and enable them to live longer and grow in size. Once roaches are full-grown adults, they can live for anywhere between 1 to 2 years.