system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Where does the web material go when a spider climbs back up?

I was watching a small house spider today drop down from the ceiling on a strand of web. I touched it and it climbed back up the web. There wasn't a loop of web dangling below it. Do they just reel it back up inside like a yo-yo? Eat it? Where does the web go?
gpt
This is from some museum entry about orb weavers:


That’s where the spider’s genius for recycling comes in. When the orb-weaver takes apart an old web, it actually eats the silk. The protein from the old silk is never wasted, from the spider’s digestive system, it goes to the silk glands to be made into a new web. Even if a spider misses a few meals, it can still go on spinning webs. This is thanks to the efficient recycling program that lets spiders conserve protein by eating old webs.