Sept. 1 (UPI) -- A Minnesota resident taking their dog for a morning walk captured video of an unusual sight: Thousands of caterpillars formed into one large mass.
The video, captured Sunday on a road in Northfield, shows what appears to be a massive worm slithering across the asphalt until a closer look reveals it to be thousands of caterpillars swarming together to move as one.
"I was taking the dog on a morning walk, when I heard something odd. I saw the source but didn't understand it. It looked like one worm, but it was hundreds (thousands?) that had merged together," the filmer wrote.
Commenters suggested the caterpillars were exhibiting a behavior where the insects on the top crawl across the ones walking on the bottom of the mass, and the bottom ones then end up at the top once they reach the back to help the whole group move faster.