How the caterpillar adapts to its habitat?

well. not all of the catterpillars protect themselves...but most of them are already green and can camouflage. other animals and predators dont see as we humans do, and cannot make the difference between a leaf and a catterpillar, or simply, the caterpillar makes a strange ultrasound that can scare or make the stupid animals flee

hope you understood what i said here...im not English :))