FACT: Zebra camouflage works because lions are colour-blind.

Sure, to you and I zebras on the great plains blend in like Richard Simmons on CNN. But when their natural predator, the lion, is completely colour-blind it’s the strong striped pattern that creates the camouflage rather than the usual technique of blending in with the surrounding colour palette. A lone zebra’s stripes break up the general shape of the tasty animal and make it harder to spot. In a herd, zebras cuddle-up close and the stripes blend together making it hard to see where one zebra ends and the next begins. (see technical illustration above)
- learn more about it: http://animals.howstuffworks.com/mammals/question454.htm

and here I thought it was so they could become camouflage with each other…
Zeebra #1 says “That’s not me- that’s the other guy your seeing…”
Zeebra #2 says “That’s not me either- we are all just one Zeebra now go away.”
The truth makes MUCH more sense then that.