Most crabs, however, are scavengers, eating dead or decaying material. There is a commercial diet available for hermit crabs kept as pets, however hermit crabs seem partial to the roots of potted plants, and have been observed to dig up plants kept in their cages. The crab's reproductive organs are situated near and just below the heart and open to the outside at the base of the last pair of walking legs in the male, and at the base of the middle pair of walking legs in the female. In most species, the female carries the eggs cemented to her undersides and protected by the flexed tail. The fourth stage of development is the megalops.
Crabs grow by shedding, or molting, their hard shells.
Hermit and other land crabs of tropical regions have adapted to life on dry land. In addition, in order to lay their eggs, they journey to the sea so that their young can spend their early lives in salt water. After reproducing, they return inland, and their young follow at a later time. Some are canned and others are sold fresh to restaurants. In the United States three main kinds of crabs are caught for their meat.