More questions from our first grade class:

Why do some spiders have 8 eyes?  How many eyes do other spiders have?


Hello 1C,

I don't know if this is the right answer, but I think that it is a sensible answer.  Spiders are hunters, and need to be able to see their prey.  The eyes of arthropods (the insects like flies; crustaceans like crabs; the myriopods, the centipedes and millipedes and the chelicerates, the spiders and scorpions) cannot move like ours.  We can turn our eyes from side to side without turning our head, because we have muscles that can make them move left and right, and up and down.  Spiders eyes are fixed and cannot turn, so to have the best view of the area around them (without having to turn around their entire body) spiders have lots of eyes (8) around their head so that they can see whatever direction lunch might be coming from.  Some of the best spiders to see this arrangement of eyes are the 'jumping spiders'.
There is a link to them below at wikipedia.  I hope that this is helpful.  Keep asking questions 1C.

Last edited by Neil Gostling (2nd Jul 2007 20:31:24)