I always call this the Cricket market. It is the only place in Shanghai where farmers who lives outside Shanghai  come and sell crickets they catch on their ground. The sell them to Shanghai people who use them for their cricket fights that are organized all over Shanghai. They do in the street, in an alley, in the door way. Two people come together create an arena and let their cricket fight. But most important is that the 2 people owners can gamble and often also other people will join. In shanghai is not allowed to gamble but when the let cricket fight it is not real gambling. You know gambling is very important for Chinese people.