By looking like a dead twig, the stick insect fools hungry birds and escapes being eaten. A few animals, however, make every effort to attract attention. The skunk ambles about the its black and white markings easily seen. Some caterpillars are so brightly coloured they can hardly be missed by birds. Why? The bold marking are a warning. The massage is clear: ‘Keep away, I’m trouble’. The skunk’s ‘secret weapon’ is its terrible smell. Then caterpillars are either poisonous or taste awful. So being the odd one out can make a lot of sense in the animal world.