Remember the last time you played hide and seek. You hid behind a bush while your friend tried to find you. If you were wearing a green dress, the chance of you being seen was automatically reduced as you could be mistaken for a bunch of leaves.
Hide and seek is a very old game and it seems human beings are not the only ones to play it. Small fish use the tactics of the game to hide from bigger ones, while moths and butterflies use them to hide from birds and other attackers.
Some creatures have colours that help them to merge with their surroundings, while others change their colour to do the same. This is known as camouflage.
The wings of some butterflies, like the curve-toothed geometer, look like leaves. They even have leaf-like veins on them. This allows the butterfly to blend into the foliage on a tree without a trace. Similarly, a goatweed butterfly fades seamlessly into a leaf litter. Some species of tree frogs can change their colour to match the colour of the trees they are sitting on.
How does an animal change its colour
All living organisms are made up of tiny building blocks called cells. All the organs of our body like the heart, lungs and even the skin, are made of these cells. A certain type of these skin cells called melanophore cells carry small packets of colours called pigments. These impart colour to the skin.
The green garden lizard owes its colour to the green pigment in its skin. These cells are controlled by the nervous system, which changes the concentration of pigments whenever needed. The colour changes depend on several factors such as the presence of light, temperature of the atmosphere, emotions like fright and a sense of danger.
So, the next time you see a war movie and find the soldiers wearing green uniform and have leaves stuck to their uniform, you will know what they are trying to do.