"The skin of a thorny lizard is totally impervious. That means it doesn't sweat or lose any water via its skin. It doesn't need much, but it needs to drink some water.
The way thorny devils drink water is ingenious, an amazing adaptation to life in the harsh desert environment. Their body is covered in a system of tiny grooves or channels that run between their scales. All the channels lead to the corners of their mouth. These channels absorb water via capillary action. (If you put a very thin straw into water some water will rise up in the straw above the water level. That's capillary action.)
Not only can the thorny lizard capture rain this way, it can also absorb dew drops, for example from the vegetation it moves through, via the capillaries. Once the water is in the grooves the lizard can suck it towards its mouth by gulping. What a design! Perfect for the desert environment."