Weaver ants (Oecophylla smaragdina) sink their mandibles into the soft-bodied larva of a tortoise beetle (Silana farinosa).
Naturally, S. farinosa larvae accumulate their feces (read: shit) and carry it above their bodies; supposedly this fecal shield protects them from enemies.
My student is examining the anti-predator properties of the fecal shield. Here she has removed the fecal shield of an innocent S. farinosa larva and placed the larva on the path of weaver ants. As you can see in the picture, the ants showed no mercy. Surprisingly (or perhaps not, knowing the aggression of these ants), larvae with fecal shield did not survive the onslaught of the ants too.
Suffice to say that with or without fecal shield, I wouldn’t want to stand against these ants.