> All of the following animals are mammals, except one. Which one isn't a mammal?Considering the nine-banded armadillo, black-bellied pangolin, hairy woodpeckerand bottlenose dolphin, the answer is: Hairy woodpecker. Despite its name, the hairy woodpecker doesn't have hair, and it's a bird, not amammal. Covered in stripes of black and white feathers, these medium-sizedwoodpeckers live in forests throughout North America, and have long tailfeathers to lean against on tree trunks.Photo credit: User:Mdf [https://commons.wikimedia.org/wiki/User:Mdf].Slightlylarger than a songbird but far more conspicuous, woodpeckers come in manydifferent shapes and sizes in North America alone. These curious creatures aremost often small, red, black and white birds with accented heads and long beaks.Their tail feathers are specially designed to support the bird as it holdsitself on a tree trunk, and have two back toes to lean back on if they getwobbly. Though hitting your nose again and again into bark would be painful for ushumans, woodpeckers don't have much of a problem. Woodpecker beaks have evolvedto help distribute the shock of the hit without taking any damage. What's more:woodpeckers actually enjoy making noise with their beaks! In the animal world,woodpeckers are the only creatures to routinely make a sound with somethingother than a part of its body. They will drum on a variety of objects tocommunicate territory, to attract mates, locate food, or maybe even play. All types of woodpeckers are perfectionists in their tree-holing craft. Manyspecies of woodpecker nest in tree cavities with access holes they carve outthemselves, and every hole is a perfect circle (Pileated woodpeckers, on theother hand, make a nest hole that is an oval or oblong). See the perfection foryourself: Photo credit: Bird Guard.