How Do Weavers Make Irreversible Knots?

Spiders wear tiny necklaces made of super-strong thread. When they tie a knot in their necklace, it stays tight forever! Unlike your shoelaces which might loosen up later, a spider's knot is like velcro that locks tight. This happens because the silk threads have tiny bumps on them. When one thread slides over another, those bumps catch and hold on like little hands grabbing each other. The more they move, the tighter they get! Scientists want to make their own knots just like spiders do for things like strong ropes or even medical stitches that heal better.