A normal crab has eight walking legs and two paws that can't walk. The crab's chest has five pairs of appendages, which are called pectoral feet. The front pair of appendages are equipped with powerful claws, which can be used for foraging. The other four pairs of appendages are crab feet. Walking depends on these four pairs of appendages. Walking looks unique and interesting, and most of them walk sideways rather than straight.

Crab's body is divided into head, chest and abdomen. There will be breastplates on the back of the head and chest, with different shapes and certain differences. There are 1 and 2 pairs of antennae in the center of the forehead, and compound eyes with stalks on the outside. The mouthparts include 1 pair of big jaws, 2 pairs of small jaws and 3 pairs of jaws. There are five pairs of chest feet on both sides of the head breastplate. The abdomen degenerates, flattens and bends on the ventral surface of the head and chest.

Extended data:

Crab habit

Crabs have a variety of food habits, both vegetarian and non-vegetarian. They like to eat animal foods such as fish, shrimp, snails, worms, earthworms and their larvae, and also eat similar animals that have been injured or just shelled. Crabs with eggs still feed on eggs when they are hungry. In the natural environment, crabs are easy to get aquatic plants, so they are mainly vegetarian. Crabs are very greedy, eat a lot and have strong digestive ability. They can eat a lot when there is enough food, but they won't starve to death if they don't eat for a few days or even a month when there is no food.

Crabs only stop or reduce their food during the winter in caves, and they also have the habit of competing for food. They often kill each other for a good meal.