@netgrrl thats actually not true at all. Goldfish are much smarter than people give them credit for, they can be trained. Pretty hard to train an animal with no memory.
@me30 I need a lot more info to actually be able to offer any help. How big is the tank theyre in? How many in there? What is the pH, nitrates, ammonia, and temperature? Filter? Airstone? Are there any visible markings on the fish? White blotches, fungus, red markings, fin rot? Does the fish look like its breathing heavy? Does it eat? How long has this behavior been going on?