Abstract: The famed explorer Charles Sturt was the first European to set eyes upon the sand dunes of the Simpson Desert, and was in no doubt about the harshness of the environment that it presents. In a letter to his wife Charlotte, written in September 1845, he described his first impressions of the desert: 'A kind of dread, and I am not subject to such feelings, came over me as I gazed upon it. It looked like the entrance into hell.' Yet dunnarts and many other carnivorous marsupials thrive in this fierce environment, eschewing fixed home ranges, evading predators and other hazards, and tracking pulses of food wherever they appear. This vagrancy, or serial nomadism, appears unique to the small mammals of arid Australia and is undoubtedly a response to the extremely unpredictable environmental conditions of the continental interior, writes Chris Dickman in an excerpt from Secret Lives of Carnivorous Marsupials.