The research examined a 2.6-gallon tank filled with either one fish, two fish, five fish, or 10 fish. Of all the pairings, the group of 10 was the "least aggressive, least likely to dart, and most likely to form schools and behave as they do in the wild." Even though the scientists only looked at neon tetras and white cloud mountain minnows, if you've ever owned fish, how many did you keep in a tank at a time?
Image Source: Getty
Latest Dogs, Cats, and Other Pets