Like most crustaceans, shrimps are omnivores and consume both plant materials and small animals. They are not picky eaters and are considered as scavengers, ingesting anything that is small enough for them to eat, including decaying matter, mud, plankton, small fish and leftover food.
Newborn and young shrimps eat plankton and marine plants, such as seaweed and algae near the surface of the water. As they grow into adulthood, their diet shifts from plants to any variety of food that they can eat. They feed on a variety of small shellfish, worms and sometimes consume smaller shrimps as well. Most shrimp species are marine animals, though some, like the caridean shrimp, are adapted to living in freshwater biomes, salt marshes, and sandy and muddy waters.