eli5: How do spiders get that single web between 2 objects so taught, the ones that you get in your face when walking through parked cars or trees?

Question

Do they shoot webs out of their butt like a grappling hook?

Do they set one side then crawl down the object and up another and slurp up the access web?

Do they all have portal guns?

Are they wizard ninjas?

In: Other

Answer 1

If the two anchor points are too far to reasonably climb, they let the wind carry a thin leader thread across the gap and then reel it back in so it’s taught. Then they use that lead to carry a much thicker and stronger thread across the gap and anchor a web.

If the anchor points aren’t that far, they can just drag the anchor fiber over manually.