Walking sticks are excellently camouflaged, and the fact that many people never see them helps them to survive. If discovered by a bird of prey, for instance, they can let themselves fall off the branch they are attached to, tightly retract their legs and lie completely still for hours on end, resembling a dry twig.
 
An insect replaces its exoskeleton with a new one as it grows, and female walking sticks do this six times and males five times before adulthood. Right after hatching from the eggs, the offspring are merely miniature walking sticks. They get a little bigger each time they moult, until three months later they are adults! 
 
Their life expectancy is only 1-2 years from egg to adulthood, when they are old and die of old age, if they haven’t already been eaten by then!