I have a community tank with a school of tetras and 3 albino corys. I got a sailfin balloon molly about a month ago and she tends to be pretty shy in general. I thought that if I got another balloon molly my original would be more comfortable around the tank. I went to my lfs and bought a black balloon molly (another female) and put her in the tank. When the mollies first found each other they seemed fine and stuck together. The black molly is definitely more outgoing and not as afraid. The next day I was watching them and I noticed that the black molly was seemingly herding the other one, and upon closer inspection the black one nips and chases the other. I've also noticed though that the other one doesn't really try too hard to get away. Neither molly bothers the other fish, and they actually hang out with the tetras at the top of the tank sometimes. Any thoughts or advice as to what is going on? I did an internet search but nothing came up with a female molly bullying another female. Do they need to be separated or are they just trying to create some hierarchy? Please help! I don't want my original molly to get so stressed that she gets sick or something.