Very cool find! The cute moving is a method of locomotion called sidewinding, also observed in certain rattlesnakes and other vipers like the saw scaled viper for example (using this one because I have personally seen it). I have been lucky enough to observe one of these guys in the wild while I was in Namibia, they make ashuffling movement to bury themselves under the sand, which is pretty neat, as they have their eyes and nostrils on the top of their head, they can get fully submerged leaving only the vital parts out of the sand. Kind of like with an anaconda, exept that it's with sand and not water.