Actually, these Calosomae don't only smell, I even saw them do the 'pinacate' walk. They would hurry forward for several inches, stop, lift their behinds, run again, stop, just like Eleodes. In the light of the early evening, this was very confusing, especially as there were at least two big Eleodes species and a Stenomorpha doing the same dance. I had just never seen any Carabidae act like that.

and black color make them good nighttime mimics of El*eodes but they also have chemical defenses of their own that must reinforce Eleod*es' reputation. I forget the name of this kind of group mimicry (Mullieran?) in which all spp. involved both derive benefit and enforce the anti-predator defenses. Maybe the Sten*omorpha was the only freeloader. (Do they have any chemical defenses?)