To effectively catch crabs, people often drain the water from the ponds, causing the crabs to gather at the bottom of the canal. At night, using flashlights makes it easier to find them.

In shrimp ponds, crabs often crawl up to the edges of canals and pond beds at night to forage for food. Therefore, people usually choose dark nights and during the tide when the ponds are empty (especially the 30th day of the lunar month) to search for crabs. Before that, people usually drain the ponds so that when the crabs crawl up to feed, they are easier to spot with a flashlight. The tools used for searching include: flashlights, nets, gloves, ropes for tying crabs, and buckets... From 8 PM onwards, crabs feed most actively, making this the ideal time to search for them.

Use a flashlight to search for crabs along the canal banks and shrimp ponds.

We had a rather interesting night crab-hunting experience with Ms. Tran Thi Ut from Tan Loi A hamlet, Ta An Khuong Nam commune, Dam Doi district. To catch many crabs, we maintained almost complete silence, gently paddling our small boat along the canal, using bright flashlights to illuminate the square fields and the canal banks to find crabs engrossed in hunting. When we spotted a crab on the shore, one person would quickly use a net to hold it close to the ground, then slowly locate the crab in the net and skillfully catch it. This method requires experience, because if not done carefully, the crab will drop its claws to defend itself, thus reducing the value of the young crab, especially during times when female crabs with roe fetch a high price.