Cockroaches do lay eggs which are bound together in a papery structure called an egg case or ootheca. Egg cases are cigar-shaped and have many tiny vertical ribs running their length. Roaches often carry the case with them to ensure the eggs hatch in a favorable environment.
Roach eggs take one to two months to hatch, depending on the species. Most egg cases contain between 10 to 16 eggs, but German cockroach egg cases can contain up to 50. Some roaches carry their egg cases with them until the young hatch, while others carry the cases only for a short period, if at all, before depositing them near food.