This cute little fellow uses hairs modified into spines for protection from predators. When disturbed it hunkers down and presents an inhospitable front to the world. It wanders around the forest looking for ants and termites, which it roots for with its long snout (to the right in the photo).
Echnidia are about the most primitive type of mammal surviving in the modern world. Unlike almost all other mammals they lay eggs rather than bear the young internally. The females have no milk-producing mammae, only patches on the skin where the milk is produced.