I saw something strange in the grass and thought it was just a rope – but when I looked closer, I screamed in horror!

What looked like a rope—or possibly a snake—turned out to be something even more bizarre: a line of about 150 caterpillars moving in perfect formation across a yard.

The eerie procession, discovered by a stunned homeowner, left many questions: Why were they moving together? Where were they going?

Experts say group movement may help deter predators, conserve energy, or improve chances of finding food. Whatever the reason, the sight was both mesmerizing and unsettling—nature’s mystery on full display, right in the grass.