How do lobsters grow?

Lobsters are crustaceans or hard-shelled animals. Lobsters, as we know, have hard shells but still they grow. The reason lobsters moult all their life. Its shell is disposed of whenever it outgrows it. The first year, it moults 14 to 17 times. After it has grown older it moults only once a year. Lobsters are related to shrimps and prawns.