Spray fenvalerate evenly in the river ditch at night, and then bury the ground cage on the shore. You can catch the crayfish that climbed into the cage and fainted the next morning. Although this method can catch shrimp, it is very toxic to crayfish, which will directly make it unconscious or even die. At the same time, the residual poison in the body can not be completely removed whether it is brewed with clear water or cooked, so it is best to use less to avoid poisoning after eating.

Crayfish, also known as Procambarus clarkii, red crayfish and freshwater crayfish, is shrimp-like and has a hard shell. The adult is about 5 to 1 1 cm long, dark red, and the shell is nearly black. There are wedge-shaped stripes on the back of the abdomen, and the young shrimps are evenly gray, sometimes with black ripples and long and narrow claws.

The middle part of the Crustacea is not separated by a net gap, and there are obvious particles on the Crustacea, and the frontal sword has a lateral thorn or a notch at the end of the frontal sword. It is a kind of freshwater economic shrimp, which is widely welcomed by people because of its delicious meat.

Crayfish inhabit permanent streams and swamps, as well as temporary habitats, including ditches and ponds. In streams, they are usually mixed with plants or sawdust, which will destroy and weaken the banks. In areas where the flood recedes, they can be found in simple caves, living in wetlands, lakes and rivers with shallow water bodies and abundant aquatic plants.