Peckhamia avoids being eaten by predators by appearing like an ant rather than a spider.
This defense is two-fold. Ants aren’t as palatable as spiders to most general predators, and spider-specialized predators might not recognize Peckhamia as food.
For mimicry to work optimally, though, spiders must inhabit places with plenty of ants. Not the easiest task, since ants eat spiders. And because most ants have poor vision, the spider’s physical resemblance to ants isn’t much help.
A new paper by Divya Uma et al in PLoS One provides a partial answer: Peckhamia doesn’t smell like a jumping spider. It doesn’t smell like an ant, either, so it’s not a chemical ant mimic. In fact, Peckhamia doesn’t smell like much at all.