5 reasons platypus are the world's weirdest mammals, not including the egg laying thing

The platypus are the world's weirdest mammals, not including the egg-laying thing.

British scientists thought they were a hoax when they first encountered them in 1799 .

They have venomous spurs and sweat milk to nurse their young.

They're almost completely blind and deaf when they hunt.

Black lights make platypus glow a lovely blue-green color and no one knows why. Another delightful mystery. All of that on top of the fact that they're a monotreme—a mammal that lays eggs— one of only five species with that claim to fame. No wonder they continue to surprise researchers just by being their cute, quirky selves..