Its not that they like gold fish, but they have a heat signature. Not a strong one but it's there. They focus on the heat signature and strike. My boyfriend taught me that trick, and it worked with the first gold fish, the second and third fish were in a fish bowl together, and the one we have left ate the other one (wtf?!). Lol. My boyfriend named it and confessed to me that he has a hard time using anything he names for food. For himself or his pets. That's when we started feeding f/t cause I knew some day we would have a collection of mice that he named. Lol.