Male platypuses have poison on their hind legs, these are glands in the thighs and the heel. The sting is not dangerous to humans but it extremely painful. They also don’t have a stomach, which means that food goes directly into the gullet which connects directly to their intestines. Their bill is made up of thousands of cells which allow them to detect electrical fields which are generated by all living things. It even hunts with its eyes closed, if it wants to!