Which of the following is not a mammal?

Only mammals grow hair or fur, but despite the misleading name, the hairy woodpecker does not have hair. Nor is it a mammal; it is a bird. The hairy woodpecker's feathers create a black and white pattern and use their long tail feathers to help them lean against tree trunks. They are native to forests throughout North America.

Although only slightly larger than a songbird (250 mm or 9.8 inches in length), the hairy woodpecker is much more visible due to the colour of its feathers and the red marking on its head. Their beaks are strong enough to withstand the repetitive drumming against the bark of the tree as they search for food (insects, tree sap etc), communicate territory or attract a mate. Woodpeckers are the only animal that regularly creates noise with something other than their internal voice box or "syrinx".

Woodpeckers also use their beaks to carve holes in trees in which to nest. Each hole looks like a perfect circle. The birds tend to live in pairs and create the nest together, where the female will lay, on average, four white eggs.