Cockroach life cycle
The key to understanding how long a cockroach lives is understanding its life cycle. Cockroaches, like most insects, go through several instars, or life stages. In each case the roaches look a little different and the process moves very fast.
Eggs
When cockroaches mate, it only takes three to seven days before the female deposits the egg capsule. The female cockroach produces an egg casing known as an ootheca. The female uses her saliva to adhere this egg case to a surface, hidden away somewhere.
More than likely, you won’t be able to find the ootheca and the cockroach eggs unless you know specifically where to look. There can be more than a dozen eggs, each containing a cockroach larva inside of it. The cockroach eggs will be hidden away, much like the cockroaches themselves.
Cockroaches are adept at hiding their eggs and their young, tucked away under sinks, within pantries. Sometimes the ootheca and eggs are so small you may overlook them if you even see them. It takes professional eyes to know what cockroach eggs look like and how to find them.
Nymphs
While the eggs gestate and the nymphs inside grow, it takes nearly a month for the eggs to hatch. This is known as the nymph stage. The young cockroaches will go through several more stages, molting (shedding their skin) and growing larger and larger until they start to look like the cockroach as you know it.
You may not even realize you have cockroaches by looking at the nymphs. Cockroach nymphs can vary in appearance based upon the species and they may not just look like tiny version of the adult cockroaches.
Cockroach nymphs can be hard to spot and identify which is why professionals are trained to know the difference between cockroach nymphs and other insect larva.
Adults
Once the cockroach reaches the adult stage, it will have wings and antennae. It will also be ready to mate and reproduce. Cockroaches may vary based upon the species of roach you have inside your home. However, common cockroaches such as German roaches, oriental roaches and other cockroaches are pretty conventional looking and like most roaches you’ve seen.
However, remember, if you see a couple of cockroaches across the kitchen floor, there may be others hidden away somewhere.