Jack Ashby

If you look at a platypus skeleton, it's covered with these lumps and bumps that attach muscle for making really, really big spade-like hands when they're

when they're in that configuration.

So where do they put the spoil, though?

Where do they put the soil?

They just push it into the walls of the tunnel.

What, they wiggle in?

They wiggle in.

So the platypus burrow is pretty much the same dimension as the platypus.

They all kind of spin around to tamp the soil into the walls.

So...

It also means that if you're a 30, 40 centimetre long animal that's burrowing for 10 metres, you don't have to move 10 metres of soil, which is really energetically costly, back down the burrow to get it out of the hole.

You just push it into the walls.

Well, it's not a very scientific thing to say, but I think they are the best animals ever in Australia.

I guess the scientific reason is that Australia and New Guinea are the only place in the world where all three groups of mammals exist.

So the mammal class is split into three groups.

Placental mammals like us, which produce babies after a long pregnancy that then finish off their infant growth by a short period of suckling milk.

And then there are marsupials, which do the opposite.

So they have a really short pregnancy and then do most of their infant growth suckling milk, often in a pouch.

And then there are platypuses and echidnas, which lay eggs.

New Guinea and Australia are the only place where you can find all three.