I have a Red-bellied Piranha that I have had for about 3 months now. Recently, I have started feeding him red minnows instead of the typical "feeder comets" from the pet store. In the past three days, he has eaten 10 of the minnows where in the past, he would eat 1 comet every week to 2 weeks. Is he going through a grown spurt? He ate 2 minnows on Tuesday, 2 on Wednesday and 6 of them between last night and this morning. The minnows were about 1 -1.5 inches long and thin. The comets he ate in the past were about the same length but fatter.