So my 40 gallon has been established for about 3 months and I have had no problems. (knock on wood). I have 5 neon tetras in there, who as of a few days ago have been acting completely normal. However, all of a sudden, its like they all got into a big argument and split up. Really weird behavior to me. Sometimes I find all of them on their own, and sometimes in small groups.They seem to be healthy, just acting sort of weird. I am probably overreacting, but I just don't want my fish to be sick. Any ideas to why this is? Thank you.