Keeping An Eye On You

This female Spotted Wolf Spider (Pardosa amentata) was sunning itself on the side of my old sundial earlier today, and I couldn’t help but notice how the one eye disturbed me a little (click on image for larger view). It didn’t look spider-like, but mammalian. I know that’s silly, but just look at it! This prompted me to ask the question, also perhaps kind of silly, which was, do spiders blink? I wasn’t sure, so I did some investigating and the answer, of course, was no. They have no eyelids to blink with, and hey, can you imagine eight of them eyeballs all blinking and winking together? Spiders are very clean animals, and they wash their eyes by wiping them with their pedipalps or even their feet, apparently. Please don’t try this at home and poke out an eye with a big toe! Use your eyelids.

This has also prompted another question. How can spiders sleep if they can’t close their eyes? Or … do spiders sleep at all? Not much research has been done on spider sleep, it appears, but they most likely have some kind of circadian rhythm.