1. You could count every species on one hand.

Today, there are only five monotreme species in the world. The platypus, short-beaked echidna are the most well-known, and can be found in Australia. The remainder, just north in Papua New Guinea, are all different flavors of echidna; eastern and western long-beaked echidnas, and Attenborough's echidna.

2. They can smell lightning.

Platypuses and echidnas have rubber,y beak-like snouts where a normal mammal's mouth would be, and they're not just for show. Those noses are packed with specialized nerves called electroreceptors, allowing them to hunt prey based on the electricity their panicked twitches produce. It would be like trying to find your smartphone in the dark by sniffing the electricity it uses when it vibrates.

3. Platypuses can see underwater. They just really don't want to.

Platypus eyes are very similar to a Lamprey's, meaning that they could very easily watch where they were going. Instead, they close their eyes and ears underwater, relying entirely on their electric snouts to find shrimp.

4. The platypus was plan-A

Fossil evidence and shows that echidnas split from platypuses between 19 and 48 million years ago. Echidnas maintain beak-like mouths with one fifth the electroreceptors of a platypus. They are also excellent swimmers, often seen paddling along the river's surface like spiny icebergs.

5. They are born tiny and naked

Baby monotremes, known as puggles are born from eggs about the size of a human thumbnail, emerging in just 10 days as writhing pink gummy bears. Their parents forgot to mention that hair goes with being a mammal, so in entrepreneurial, 3 month old puggles set out to grow a full pelt in time for their first birthday.

6. Platypuses have toxic roundhouse kicks.

Although most wild animals don't want to be touched, platypuses take it one step further with a set of poisonous spurs on their hind legs. The poison isn't deadly, but it is extremely painful. Imagine getting injected with hot sauce while your youngest sibling kicks you repeatedly in the shins.

7. They are very cold.

At 90 degrees Fahrenheit, monotremes have the lowest average body temperature of all mammal groups. This is where hypothermia starts in humans, so don't try to be as cool as a monotreme.

8. They have one hole to rule them all

The name monotreme itself means one hole, and they are adamant about living up to the title. Like birds and kangaroos, monotremes do all business of the lower end of the body through an all purpose opening called the cloaca.

9. They are evolutionary rebels.

It's a common misconception that monotremes are made of leftovers from the time millions of years ago when mammals first scampered into the fringes of the food web. However, like marsupials, monotremes decided that placentas were too mainstream, but they took it one step further, shunning pouches, live birth, and nipples to excrete milk from.

10. They sweat milk.

Despite the lack of nipples, monotremes didn't give up on feeding their babies milk. Instead they leak it from specialized pours near a pouch at their rears. Puggles simply lap it up as it pours from their parent's pores.