Deep Look | These Silk-Swinging Caterpillars Will Ruin Your Picnic | Season 8 | Episode 1 | PBS

California oak moth caterpillars eat all the leaves on an oak, leaving a brown skeleton. Then they rappel down on a strand of silk, twirling and swinging. If you were enjoying the shade, good luck getting out of their way. For the oak, the caterpillars are a bigger deal –– will the tree survive?