2. The ground cage is made of steel bars with a diameter of 6 mm, and processed into a square frame with a length of 40 cm, each 50 cm is a section, connected with steel ropes, and then wrapped with polyethylene mesh cloth, and the two ends or the middle of the net are made into net bags. Each section has an entrance, and the frame and the mesh of the frame are made into whisker doors, so that shrimp can only enter but not exit.
3. The shrimp inlet directions of every two connecting sections are opposite, so that fish and shrimp in two directions can be caught. The length of the ground cage can be determined according to the length and width of the aquaculture water surface, generally about 15 knots, with a total length of about 7 ~ 8 meters. The ground cage is a fixed fishing gear, which can be caught all year round. Place the ground cages in aquaculture or natural waters such as ponds, lakes and rivers, and dump the fish and shrimp in the net bags every morning, take the big ones away and put the small ones in.
4. Put bait through the bait column in the shrimp cage, close the shrimp door, and then put it into the water where the shrimp gather. Shrimp is attracted by the scent of bait and enters the shrimp cage from the inverted whisker mouth to eat. The outlet of the inverted whisker mouth is funnel-shaped and the inlet is small, so it is difficult for the shrimp to find the small mouth at the bottom of the inverted whisker mouth, and the shrimp will never come out again. Lift the shrimp cage out of the water and open the shrimp door.