I have 3 ocellaris clowns. Two were given to me and I had the 3rd one. After a lot of reading while they were in QT for a month I decided to go ahead and add them to the tank with the other and we have never had any issues. Today I noticed the one of the two I got together keeping the other one down in a bolt hole. Later, I saw the one bite the other on the tail and hold on. The third one (my original) seems like a bystander. Should I pull the one out? It could go in my QT. Or should I say this is mating/courting behavior and just let it alone?