Crabs are generally omnivorous and have a diverse diet that varies depending on their species and habitat. They eat a wide range of foods including:

• Seaweeds, algae, and plants
• Worms, shrimp, and other small crustaceans
• Small fish and other crabs
• Mollusks such as clams, mussels, snails, and oysters
• Hard-shelled animals like barnacles, sand dollars, and starfish
• Carrion and decaying plant matter (scavenging behavior)
• Eggs and sometimes even their own kind

Specific examples include:

• Dungeness crabs eat starfish, crabs, squids, worms, fish eggs, and sometimes other Dungeness crabs.
• Blue crabs consume snails, dead animals, fish, crustaceans, plants, and occasionally other blue crabs.
• King crabs feed on sand dollars, barnacles, clams, mussels, worms, sea urchins, and snails.
• Hermit crabs eat fruit, leaves, plants, grass, and protein sources like eggs and shrimp, often scavenging washed-up organic matter.

Crabs hunt along the sea floor or scavenge for dead matter, using their claws to catch or break down food. Their diet is highly adaptable to their environment, with marine crabs having a broader range of prey compared to freshwater species that rely more on vegetation and insects