There are several stages in the life cycle of a cockroach, and it takes about a year for them to grow into adults and their life cycle only lasts from about 18 months to two years.
Cockroaches are born as eggs in small cases that contain approximately 40 eggs each, and are laid by the mother in warm and moist places. It takes about six or seven weeks for the baby cockroaches, now called nymphs, to emerge from the eggs.
They remain in the nymph stage for approximately one year, and during this time they molt or shed their outer skin about eight times.
When they grow into adulthood they are ready to reproduce and they generally live for another 6 to 12 months, so the total life cycle is 1 1/2 to 2 years.