The main foods of crabs are small fish, shrimp and seaweed. Crabs spend most of their time looking for food. They are generally not picky about food. They can eat all the food they can find with their claws. Small fish and shrimp are their favorite, but some crabs eat seaweed, even animal carcasses and plants. Crabs eat other animals, and other animals may eat crabs. For example, humans regard crabs as delicacies, and waterfowl also eat crabs. Some fish like to eat crab feet just like humans. Young crabs and underage crabs may be preyed by other marine life when floating in the sea in groups, so crabs should lay a lot of eggs when laying eggs to ensure the survival rate of crabs. Extended data:

Morphological characteristics of crabs Although crabs are small, they are complete. After removing the hard shell of the crab, we can find that the body part of the crab is protected by a shell. These shield-like shells are called crustaceans by biologists. Crabs are symmetrical and can be divided into forehead area, eye area, heart area, liver area, stomach area, intestine area and gill area. The two sides of a crab are connected by appendages. The appendages of the head are called tentacles, which have the functions of touch and smell. Some appendages have the function of mouth, which is used to tear food and send it into the mouth. Crab chest has five pairs of appendages, which are called chest feet. Based on the characteristic that the two feet at the tail of crab seldom participate in walking, a 6-foot lateral moving walking mechanism was developed by imitating the walking mode of crab, and its motion characteristics were studied to meet the requirements of walking on rigid ground and soft ground in agricultural production.