In my tank, I have 4 fish and 2 shrimps. I have my two platies which I initially purchased. They are both males. The platies are looking healthy, the water parameters are good, they are eating, there are no signs of aggression, however I noticed that a majority of last night and all day today, one Platy has been continuously swimming up and down the glass, quiet erratically, non-stop. He's doing nothing else at all except for eating.