Stick bug...

Stick bug...  My mom (who lives near Charlottesville, Virginia) sent along this photo of a stick bug she spotted on her house (click to embiggen).  What a monster!  I remember these when I was a kid in New Jersey, but I haven't seen any in either California or Utah.

Their appearance is a defensive mechanism; it makes them hard for predators to spot.  Stick bugs eat leaves, and mostly at night.  During the day, they mostly stay still, the better to foil the predators that would like to eat them...