you know its the strangest things that will set off a trigger. my trigger fish is set off by fish with big paches of the same color. but the good thing about the humu humu is that it doesnt become a serial killer in a few years it stays the same for its entire life. the down side about them is that they grow annoyingly slow. if well fed(do not underfeed it, it will live a shorter life if you do) it will grow bout half an inch a year untill they reach about 5'', then they slow down even more! but they are tough fish and fun to have. ther personalitys are all different. they will even let you pet them.