hehehe yeah! I was abit shocked when they are nipped my arm by mistake while I do my cleaning lol it's quite a powerful bite from them, no bleed but do give me a good freaking feeling when they do that
I'm glad they are not a real Piranha.....
Update:
There is a pair that close to 3 inches and I think they are male and female. I don't think they are going to spawn but in case that gonna happen then I have no way to get them out to a breeding tank without tear apart of my tank decor
and I don't want to do that.
Also, these grow quite fast if given them a right water condition, good diet and they not even salvage each others like some folks experienced.