I took the female betta out of there already and he still does it. He goes back into the water when he feels like it. I'm starting to think this is a natural habit kind of behavior. He seems to really enjoy it so I rather not raise the water level.Might be scared of the other fish in the cup. I'd just raise the water level so that there isn't a ledge for him to get stuck on and throw some plants in there for shelter.