Boris the Spider (creepy crawly creepy crawly)

You ever get the feeling that something is crawling on you, so you look at your leg to see what it is, but there's nothing there? And even as you're looking at your spider-free leg you still feel something crawling on you, as if the spider is invisible? You feel it, but you can't see it, so your eyes and your skin are at odds.

What's that about?