A crab pot works like any other crustacean pot, including lobster traps, prawn traps and some minnow traps. The crab pot uses a system of nets inside a large metal cage made of wire or flat metal mesh that is reinforced with steel bars. The traps or pots are designed to allow crabs in but not let them out. This is achieved by careful positioning of the bait and "leads," which are the sides of the entrance to the pot. Pots can be made any size, though there are some regulations for overall size, net hole size and requirements for organic "escape" hatches or breakaways so crabs can escape if the pot is left untended.
Netting the Catch
A crab pot is a large square about 2 feet high and 8 feet wide. Two ends have lead-ins that angle into the trap from the sides and bottom to a narrow slit about 2 feet into the pot. This slit is the only entrance into the trap. The crabs realize they must crawl up the leads to get to their free meal. When they crawl through the narrow entrance slit, which is just wide enough for them to crawl through, they fall to the floor of the trap. It is impossible for the crabs to jump or climb back up to the entrance slit to get out of the trap, since it is suspended off the floor of the trap.
Pot Size and Fishing
Once inside the trap the crabs can eat the bait, which is hung in the pot. After they are full, they continue to look for a way out, crawling all over the trap (but never out). As more crabs crawl in, the trap fills up. Most pots use a large inside area to hold a large number of crabs. Some will use a number of entrances on all sides of the pot, as well, so more crabs can get inside the pot faster.