Big Eyes in the Butterfly Garden
Updated: Apr. 24, 2020
Butterflies and caterpillars use “eyespots” to scare off predators in the butterfly garden and beyond!
“My, what big eyes you have!” I say this nearly every time I encounter a Spicebush Swallowtail (Papilio troilus) caterpillar, like the ones shown below. Those aren’t eyes, though – that’s just what the caterpillar wants me to think. Instead, they’re a clever form of defense known as “eyespots”, and many caterpillars, butterflies, and moths use them.
![Eyespots in the Butterfly Garden](https://www.birdsandblooms.com/wp-content/uploads/2014/07/Eyespots-in-the-Butterfly-Garden.jpg?fit=628%2C416)
Eyespots are pigmented areas on an organism’s body designed to look like big eyes, in an attempt to fool predators into thinking a creature is much larger than it really is (Spicebush Swallowtail caterpillars are sometimes known as “snake caterpillars”). The actual eyes of those Spicebush Swallowtail caterpillars are about the size of a pinpoint, and are located lower down on the head, closer to the mouth. The eyespots are much bigger, and when the caterpillars are on a leaf of the same green shade as their bodies, the eyespots are the first thing a predator will see. With any luck, it will cause them to back off and seek a meal elsewhere.
![Eyespots in the Butterfly Garden](https://www.birdsandblooms.com/wp-content/uploads/2014/07/Eyespots-in-the-Butterfly-Garden-2.jpg?fit=628%2C416)
Adult caterpillars and moths use eyespots too, but they display them on their wings instead. Large eyespots can fool a predator into thinking they’ve disturbed a bird as large as an owl, rather than a small a relatively defenseless butterfly. Even if they don’t avoid the butterfly or moth entirely, the predator may be fooled into attacking a wing instead of the body, injuring the insect but still leaving it able to fly away and live another day.
![Eyespots in the Butterfly Garden](https://www.birdsandblooms.com/wp-content/uploads/2014/07/Eyespots-in-the-Butterfly-Garden-3.jpg?fit=628%2C417)
Have you ever spotted any “big eyes” in your butterfly garden? Tell us about it in the comments below!