All three of them will hang together while picking at the back wall, I am sure that they each have their own territories in the tank. I knew about what everyone says about multiple dwarfs but personally do not think that it is a harden fast rule that more than one cannot coexist. Every tank that I have had housed more than one dwarf, mainly because there are so many that I like it impossible to choose just one. The tank is a little bigger than a 65 gal footprint also. It's 5' x 18" x 30" but still not a ton of swimming room. Probably just looks shorter because of the height.