Insects in the Phasmid order received their more commonly used name “Walking Sticks” because …well, they generally look like sticks, leaves or tree bark.
In an order of insects that look like plant parts, it may come as no surprise that their eggs have evolved to look just like plant seeds. While you might guess that this is simply so the eggs will blend into their environment, that’s only a small part of the story.
As an example, take the female Australian Walking Stick.
The seeds her eggs resemble have a fleshy cap that’s rich in lipids and proteins, and is a favored source of food for ants. Aside from looking like a seed in shape, coloration, and size, the Australian Walking Stick’s eggs have evolved to have their own detachable cap (called a capitulum) that’s also prized by the hungry ants.
So, as the ants go about their business of collecting plant seeds to feed their colony, they inevitably collect the lookalike eggs. With only the eggs’ cap being consumed by the ants, the rest of the egg remains unharmed and, more importantly, now inside the protection of the ant nest where it continues to develop.
If you thought this example of an Australian Walking Stick’s body and eggs resembling plants and seeds was amazing, take a guess as to what the walking stick nymphs look like when they first emerge from the egg.
An ant.
Blending in with the rest of the colony, after hatching, our tiny imposter will emerge from the ant nest, climb into the surrounding vegetation, and eventually take on a more stick-like appearance as it grows.
Stick insects …the masters of mimicry!