Instead of standing out with their warning-I'm-yucky colors, these critters use the blending-in technique to avoid being eaten. Those who look more like their background survive to reproduce (and thus pass on their advantageous genetic code). As they sing in the hokey-pokey song: that's what it's all about.
All photos taken in Sabino Canyon by Ned Harris. If you haven't already spent a happy hour here, I highly recommend it.