I love watching my red tail shark, who has grown quite large and is incredibly beautiful. He has decided to take over a second cave - his first being a black UV plumbing elbow covered with rocks. Now he commutes to his summer home across the tank - a coffee mug with a rock covering part of the opening. It takes a lot of energy for him to guard both these lairs. No sooner does he leave one than my three clown loaches go for a swim through it, which makes him crazy, so back he goes, leaving his second cave unguarded. Of course the clown loaches merrily go over to that one. (Meanwhile, the clown loaches have about three caves of their own....)