I recently started my first aquarium. It's a very small 5.5 gallon tank which has been running for a couple weeks now. On the weekend I bought my first fish: two head & tail light tetra and one black neon tetra.

I am very new to the hobby and don't know very much about fish behaviour. It seems to me that one of the head & tail light tetras seems to be dominant over the other two. It tends to eat the most and chases the other two into separate corners of the tank while it occupies the central portion of the tank. The other two swim around a bit but tend to spend a lot of time in opposite and sometimes the same corner of the tank.

Is this common behaviour for tetras? Does anyone have any suggestions or advice?