Caterpillars might fly - Telegraph Caterpillars are becoming emblematic of our age, though who can say why? A father with a birthday cake for his nine-year-old son on holiday in Alicante set off a machine at the airport that detects explosives. The cake did not explode, and nor did anyone else. After a delay, all was settled amicably. It happened to be a Wiggles the Caterpillar cake, but that is not thought to have been the deciding factor. Would the alarm have sounded had it been a Colin the Caterpillar cake? Colin, we are told, is what he eats. So, as long as he has not been eating anything resembling explosives, it should be all right. Rather confusingly there is also a vegetarian version of Colin the Caterpillar sweets, in the shape of butterflies. Are butterflies any more proper vegetarian fare than Percy the Pig sweets? This could be a heated debate, but, like the caterpillar cake, not, we hope, explosive.