A she-sparrow eyed a spider that hung in its web.  As she stretched her neck forward toward it, the spider vanished into a brownish blur, vibrating like sand on a drum-head.  The sparrow drew back, cocking her head and looking stupid.  A spider body came back into focus.  The sparrow stretched forward again and again the spider blurred.  The sparrow sat perplexed for a moment before some distraction sent her flitting off noisily with the other sparrows.  The spider hung in its web.