Hello everyone. I am fairly new to the Piranha hobby. Ive had 3 baby reds for about 5 days now. 2 of them are about 2", the other one is 1.5". Now, for some reason the smaller one is always swimming around my tank, eating like a fiend when I put food in, and chases the guppy I have in there. While the two other bigger ones hang out around my heater, not doing much of anything. Is this normal? Ive also noticed on the larger piranha they have had some their tail fins bitten off, but the smaller one hasnt been touched. Any idea whats going on?