Spiders make traps using light

Some spiders "decorate" their Webs with zigzags and spirals, but the reason why has remained a mystery. Researchers from the University of Sydney now think that the web patterns may be used to reflect ultraviolet light in a way that helps nab insects. From National Geographic:

The team concluded that the webs may be essentially setting a "light trap," where the reflection of the web strands lure passing insects to their deaths.

"Interestingly, the webs [decorated with crosses] were a little more sophisticated than we first thought," (researcher Dieter) Hochuli said.

"The spiders seem to be exploiting the sensitivity of some prey to UV light in particular. When we filtered different components of the visual spectrum from webs … we dramatically altered prey-capture rates," he said.

Link