why are my community fish are becoming agressive?

Question

i have a tank with some different types of community fish, we have had these fish for a couple months but lately they have started to become more agressive with each other. could this be caused by overfeeding (my parents feed them way too much) what should i do

i have 2 balloon belly mollys, a couple platys, neons, and some tetras

the mollys and the platys are the ones that are being agressive

Answer 1

what kind of fish do u keep??
overfeeding has nothing ot do with aggresion
maybe they are just breeding

Answer 2

i had a similer probelom. I have a 5 gallon tank. One of the 3 platys I had was preganant so i wanted to get another fish so the daddy fish would have company. the 2 other fish I had were tetras. The daddy fish attacked the new fish i put in there. and the new one died. try having equal amounts of the fish. like exsactaly 4 mollies and excatally 4 mollies or somthing like that. I bought my fish in pairs of 2 and they never fight. but then when I put the new one in the dad fish was bumping it against the wall.

Answer 3

Without knowing which fish you have these are just guesses though the fish could have become sexually mature and what seems like bullying is just courting or mating, the fish want to breed and are therefore becoming territorial, the fish you have are fin nippers like Tiger Barbs and are now comfortable to start harrassing the other fish, there are several other possibilities though these cover most of them. If you let us know what type of fish you have that would really help. Some fish do great in schools of at least 5-7 are act aggressively if there aren't enough of it's own kind to feel secure. etc. etc.

Answer 4

I'm guessing there are not enough hiding spots for the tetras or personal spaces for the mollies
Tetras are known to become territorial after they have acclimated to a new tank environment. Mollies will defend food sources.
See if you can add some big rocks for nooks and crannies for hiding places for the tetras and mollies. They will separate themselves and hide and reduce the aggressive behavior. If they don't, it will become survival of the fittest and kill each other in the process (mine did - I have one survivor. He tried to attack my tinfoil barbs, who ganged up on him and chased him back, now he leaves them alone.) So see about adding some big rocks set up as a reef or rock wall and your fish will begin establishing their personal spaces and peace will be restored.

Answer 5

change up the decorations b/c they're starting to claim territories. add new stuff in the tank if you can ... like rocks, drift wood, plants, etc.