I've never kept only 2 flags (had a dozen or more in a 110 gallon tank yrs ago, when I lived in Florida (found em in a ditch). The store had 4 flagfish, one female and 3 males and the males were chasing the crap outa her. I had planned on getting 6 or 8, but opted for just a pair. She seems much more calm now in the QT tank than at the store with all that attn. So cute how she follows the male around. It's almost like she's the puppy onna leash, out for a walk with her owner!