Most animals have skin colour that makes them merge into their surroundings. They become near invisible unless you look very closely. But some reptiles such as the sea-snakes, coral snakes and frogs of Central and South America are brilliantly coloured or have bright bands like deep yellow, orange, pink on their bodies.
They are easily visible among the green leaves or brown earth. This is because these animals are poisonous. The colouring is a warning to other animals, especially their natural enemies, to avoid eating them. The frogs of Central America called the dart-poison frogs secrete a poison from their skin.
The bright colours of the reptiles act as a warning to would-be predators to avoid eating them. The poison from the skin tastes so awful that the bird or snake quickly spits out the frog before the poison can take effect. Birds and other snakes learn to avoid these bright frogs and their poison.
It is interesting that similar bright colour patterns have been developed over the centuries by many non-poisonous animals too as a survival mechanism to fool predators. Since predators avoid attacking these brilliant coloured animals, thinking of them as poisonous, these animals, too, escape getting killed.
Even in the inset world, harmless insects, butterflies and moths mimic their poisonous fellow beings. The imitator is protected not only by the colouring and shape but also by the predator’s experience with the poisonous kind – once bitten, twice shy!