This is simply the question that seems to be tied to cats the most. The simple answer is it's a toss up really. They are all different. However, one way to solve this is less hidding spots. The more you provide the less you will see them. So for example instead of a driftwood that they can hide under you should use a rock. Dont' create holes for it to go under and hid. Place the rock in there flat if possible. That way the cat will go behind instead of under it it won't really have a place to hide. It'll be more active and swim about more. It worked for me. Also leaving the light on more often may help too. In my bigger tank of cats I provide no hiding spots no drift wood or rock they are way more active.