Fish have different daily schedules. Some are more active at night (nocturnal), some are more active during the day (diurnal). As you might expect, fish that hunt by sight are active when it’s light out. So a goldfish is active in the day.

Do you want your fish to actually “listen” better or do you want them to pay attention to something? Visual cues are usually more important than sounds to a sight hunter like a goldfish. People have had good luck training them with things like small flashlights as cues.

For example, the next time you feed your fish, turn on a small flashlight at the same time you feed the fish. If you do this every time, fish will soon learn to associate the light with a food reward. This is called “classical conditioning.” It’s like getting a happy feeling when you hear the ringtone of your favorite person, even if the sound itself isn’t that great.

You can use a “target” to train your fish to do many things. Your target could be a waterproof light, the beam of a laser, a stick, or something else. Gently put it close to the fish or close to food. If the fish touches it, drop in a food pellet or flash the light, then give a pellet. Try this a couple more times, then take the target away. This is called “operant conditioning,” training an animal to do something to get a reward.

Wait until the fish is hungry again, then repeat the whole thing. Gradually move the target farther from the fish so that it has to travel to get to it. This is called “shaping” a behavior. You start off with the simplest first step possible, then gradually train the animal to do a little bit more for the same reward. Each training session should be short so that the fish does not get tired or full. Now you can use the target to make the fish swim to a certain place, or in a certain pattern.

I teach biology at a college. I have a master’s degree in zoology (the study of animals) and a doctorate in ecology (the study of relationships between living things and their environment).