Do clown fish sleep? Or is it the white spots disease? I am treating my ocelleris clown fish for it. Hepl!?

I am treating my clown fish for white spots disease, and he seems to have lost most of the spots that were on him. Now he does this thing at night when i turn off the lights in the tank. He goes to a corner or near the gl walls of the tank and squirms around. he rubs up against the walls, and the sand. Is he itching because of the white spots disease that he might still have? Or is he getting ready for bed or something. I don't have an anemone for him yet so he might be scared or something that he doesn't have one to sleep in. Lastly, should i keep treating him for white spots, because i don't want to waste the formula if he is just snuggling up in the sand for bed. Help, and thanks you for helping!