Australian Thorny Devil Moloch horridus picured in Western Australia. This Australian reptile is one of the most desert-adapted species on the planet. Thorny devils have a hygroscopic system of grooves in their skin that lead to the corners of their mouth. Bentley and Blumer (1962) showed that thorny devils take up water by means of capillary action via these grooves. Thorny devils use a gulping oral mechanism to move water along the grooves and into their mouths. Thorny devils can drink water from dew that falls on their backs.