A “poop” shield will keep predators at bay!
By Dr. Neil Dan Fernandes

The caterpillar of the Commander (Moduza procris) butterfly is well known for its ingenious method of concealment.

In order to camouflage and protect itself, this caterpillar eats up a part of the leaf it is on and strings up its droppings with silk to make a "frass" (poop) barrier! The frass pellets are approximately the same size, shape and color of the caterpillar and serve as effectivedecoys or “dummy caterpillars” protecting the caterpillar from predators.

Upon closer examination, the real caterpillar can often be found resting on the midrib of the leaf, where it is perfectly camouflaged, behind its “poop barrier. The caterpillar’s dirty brown-black color and short spines break up its outline, making it indistinguishable from the surrounding frass pellets. Research has demonstrated that the frass barrier also effectively deters ants, who find the droppings repulsive.