Shrimp live underwater in rivers, lakes and all major oceans depending on their species and where they breed, hunt and live from day to day. Shrimp are small crustaceans and are a prime food source for many large animals. This includes shrimp krill, which some species of whale consume by the millions each day.
Like all crustaceans, shrimp shed their old carapaces as they grow larger. New carapaces are vulnerable after molting until they have a chance to harden into something that can protect the shrimp. The discarded carapace is often eaten by the shrimp to reclaim nutrients.
Shrimp are predators in their own right and feed on a large number of different prey animals. Freshwater shrimp such as the crayfish feed on frogs, tadpoles and even small fish. Their sharp claws allow them to seize and tear apart soft-bodied prey, including other crustaceans who stray into their territory.
Some shrimp move together through the ocean in massive colonies. These colonies descend on food sources and strip them dry, but on a day to day basis they feed on phytoplankton, tiny vegetable organisms drifting through the ocean. These shrimp are often preyed upon by fish, other crustaceans and mammals like whales and dolphins.