I was in the arena playing against a psiontal, and had an almost full field of scarabs, two of which had mitosis (I don't have a screenshot, sorry). The opponent had run out of all their psions, but i was trying to stall their death so i could completely heal myself and get EM, so i had my scarabs eat eachother. But as soon as i used just one of their abilities, all the rest couldn't use their's either. The game seemed to think that i had used all of the scarabs' abilities when i used one, but none of the others got the devour bonus. It happened twice.