So it is possible for the zebra to merge into the grasslands and become invisible to untrained observer. Another trick of the camouflager is countershading. This occurs when the coloration of the upper parts of an animal is darker than it s undersides. Hence the effect of sunlight is counteracted. The normal casting of a shadow on the ground is distorted and the animal is not given away by its shadow.
Some animals merge with their background by the use of just a single color.
The polar bear merging into the snows of the Arctic are an example of this, as are the grasshopper and the parakeet. Among the insect world, a common form of camouflage is mimicry. Here an insect will becomes a part of the surrounding environment, mimicking its behaviour. Stick insects, for instance, become parts of a tree. Leaf insects so closely resemble the greeny leaves of a tree, with their shape, markings and movements that other insects have been so deceived that they have actually nibbled on the insect.