KamovInOnUp t1_ivu6b2z wrote

Their native habitat is the hard-packed deserts of Australia. It rarely rains there and when it does it comes down hard and floods the hard ground. Because water is fairly scarce beardies hold in their poop for as long as possible, to not waste any water.

When it rains and floods the water touches their bellies which triggers them to put their heads down and drink until they're bloated, as well as to finally poop.

If the water is too high they'll take a deep breath to inflate like a life raft too, which is pretty cool.