+1 earlier posts!
Murderous little beasts. I once made the mistake of putting two juvenile convicts in a tank with Leleupi cichlids. The Leleupis were semi-aggressive, and I thought the two species would nose each other a little, then settle down to a more-or-less peaceful stand-off.
Nope. The juvenile convicts were maybe an inch long. The Leleupis were 4 - 5 inches long. The convicts relentlessly harassed any of them that dared come near the convict corner of the tank. Gave the convicts away, because of it.