Q. If coconuts have hair and produce milk why they aren't classified as mammals?

Fun question. As it turns out, according to the book Mammalogy, mammals are required to also have three middle ear bones, a neocortex (and therefore a brain), plus mammary glands. They even have to have a sense of smell, skeleton, and other elements missing in the typical coconut. This leaves the poor Cocos nucifera, despite its shaggy appearance and quasi-milk, out of the running to be a mammal. But the good news is that it still has the distinction of being the largest seed in the world, if you include "sea coconuts."