my african knif up till about a month ago never camout till it was dark some mornings i would c that he had gorged hisself on the pellets i dropped in but now he comes out like the rest of the fish when i approach the tank and has even snapped at the other fish..like my 6 inc parrot or my 7 in rainbow cichli and the others all aroun like 4 to 5inches..to get the food i put in for the top feeders,,and after that he searches the bottom for any thing even if stomach full.snapping at the skittish fish hes at about 12 13 inches might have to get rid of him he in my 220gl