Some background .. I bought 2 Bolivian Rams a couple of weeks ago, hoping for a pair but hard to tell in the LFS as there were a lot of them in the tank. The guy there seemed to know a bit about them and went with two he felt were the "best chance of being a male and female". In my tank now, I believe I can see one is clearly a male based on the shape of his vent, the other one I am not so sure. My question .. today the male starting building a hollow in the gravel under a crypt plant, using his tail and physically moving the gravel with his mouth, piece by piece. Pretty cool to watch. So is it safe to assume the other is a female and he is provoked to doing this? Or do they sometimes do this even when not paired? They are in a community tank, 33 gallons.