neon tetra behaviour

[lionheart]

hi can any one tell me why my neon tetra's are being aggresive towards each other, when i first put them in tank they stayed together in a group and did very little,there are 5 of them and in last 3 days or so there behaviour as become eratic,they very seldom stay together as a group, they seem to be getting aggresive towards each other they do there play thing chasing each other around the tank, but also they seem to be staking there own little territory's out individually,when ever one of the other tetra's enters anothers space they nose dive them in a aggresive manor until they leave that particular area in which they are in,there colours are as they should be very bright so they are not stressed by this behaviour pattern from each other,conditions as follows- water temp 74 amonia level o nitrite 0 nitrate 5 i do a 1/3 water change weekly,there are numerous plants for shelter for them i have light on about 6 hours daily and feed them flake once a day,so if any one can shed any light on why they are behaving this way towards each other it would be of great help as there aggresive-ness is a concern and i fear they will injury each other,i also must add they have the tank to them-selves no other fish in tank and the only time they seem to group back up is on evening when the lights go out,also when i feed them the flake - its like watching great whites on a nature program in a frenzy feed, thanks in advance for any replies much appreciated!!!!!!

 

[aveldina]

I have not owned neon tetras, but I do have red eye tetras in a group of 7, and their behavior is very similar to how you describe yours. They don't normally school together unless they are scared for some reason. Normally they simply pick out their own little spot and zip around chasing each other. This seems to be pretty normal behavior for them. Mine also do feeding frenzy as well.. last night one actually managed to splash water out of the aquarium while dashing at the food. Anytime I have had real aggression issues with fish there have been signs of physical damage from attacks such as ripped fins. My tetras have shown no such issues despite the speed at which they dart around the tank.
Their little games of tag are always the best right after I do their weekly water change, they have this little extra burst of energy. It's neat to watch.
Oddly enough, they never go to the top of the tank during the day, yet at night at least half of them sleep up there. I still don't get it.