My daughter stepped off of the school bus the other day, handed me her heavy backpack, and – as is her custom – made her way slowly up towards our house by walking on top of the rock wall alongside the driveway. As she neared her destination she stopped, dropped into a squat, and called the rest of us – her sisters and me – over. She’d discovered two inchworms hanging from their invisible filaments over the edge of a large rock. For the next ten minutes, two of my daughters remained there, transfixed, watching the two inchworms “race” up and down their threads.