To defend themselves, orb spiders build body doubles out of bug corpses and silk. To us it looks like bundles of junk have cluttered up their webs, but to predators those lumps of moldering insect pieces look just like lunch. That's because orb spiders, like all spiders, have bodies that reflect ultraviolet rays. By wrapping up bundles of trash with UV webbing, orb spiders are creating decoys that are not only the same size, but also the same color. The dummy spiders are such a good distraction that wasps will attack the wrong target 60 percent of the time. They're basically guessing.
BBC Earth News
Totally not creepy and disturbing at all.
Possibly even more unusual, the common garden spider has been known to trick insects into thinking its web is a flower. It turns out that flowers give bees and other insects explicit instructions on where to find the good stuff. They use UV coloring to highlight their nectar snatch. Striations in their petals that botanists describe as a "bull's-eye pattern" guide pollinators exactly where they need to go. It's like landing lights for bugs.
"Be the flower, Frank. Be the flower.