Aggressive molly, anyone else with this problem?

[Regen311]

From what I've read, Mollys are supposed to be peaceful fish. That wasn't the case with the fish I got. I originally had 1 male molly (who was actually quite large) and 1 female molly. I added what I thought were 2 more female mollys, because I've read a good ratio is 3 females to 1 male. This is a 10 gallon tank by the way. It turns out, the woman at the pet store (who I had specifically asked, "do you know the difference between male and female mollys?) had no clue because she gave me one male and one female, leaving me with 2 males and 2 females. The male I added was 1/2 to 3/4 of the size of the original male. After doing some more research, I learned how to tell the difference and identified that I definately had 2 males and 2 females. The original male terrorized the new male. He wouldu search the tank for him and when he found him, dart at him and chase him around the tank. After a few days, the new male found a hiding place under a decorative rock and would not come out, even to eat. I took the original male out and gave it to a friend whoh has a tank set up already. The new male took a few days to come out of hiding, but is now eating and lively and happy. I understand that the issue was definately having the 2 males together, but I had never heard that mollys are aggressive at all. Why are they listed as community fish if they are so aggressive towards each other like that? Or, was my fish a rare exception? Anyone have similar experiences?

 

[Menagerie]

When you have two males and only two females, territorial aggression will come out. With that tiny tank, there was room for only one male.