Cankerworm antics

We have some cankerworms dropping by silk threads this time of year. I was watering some newly planted grass and gave a quick spray towards one little green worm. It immediately shot back up the thread a foot or so. I can see how they exude the silk to begin with by squeezing it out of glands, but how in the heck can it suck it back in, and very quickly?


They don’t suck it back in. They climb it, using their legs.