Diapause is a stage of suspended development. Under unfavourable conditions many zooplankton species in lakes and ponds are known to enter diapause. Diapause occurs also in certain insects, fish and nematodes. Diapause guarantees survival of offspring during intense periods of predation. Duration eggs may be ingested by predators; however, they are not digested and are still viable after passing through the intestine.
Metagenesis is the alternation of polyp and medusa stages that occurs in cnidarians. Hibernation is the winter sleep. Migration involves the movement of organisms temporarily from the stressful habitat to a more hospitable area and their return when stressful period is over.