At the time of copulation, spermatozoa mixed with nourishing fluid. The spermatophore is transferred to the female genital pore and finally get stored in the spermatheca. Fertilized eggs become surrounded by collaterial glands, which forms ootheca. In each ootheca, 14-16 eggs are arranged in two rows. The female carries ootheca near her abdomen for several days and then lay them near a moist and food environment. The developing embryo of a cockroach is called nymphs. This nymph undergoes morphological change around 13 times to attain an adult form. This mode of cockroach development by various nymphal stages is called paurometabolous.