Insectivores: A sticky tongue
A few insectivores specialised in eating one particular kind of invertebrate, ants and termites. In order to do this a long, sticky tongue is required. Many unrelated creatures, specializing on this diet, have independently evolved such an organ. The numbat, the marsupialant-eater from Australia, the monotremeechidna and even ant eating birds, woodpeckers and wrynecks, have developed one that fits inside a special compartment of the skull and in some extends round the eye sockets.