Inhabiting the planet Mote Prime and most of the habitable orbiting bodies in Mote System, as well as many artificial orbiting constructs, the Moties' primary distinguishing physical feature is their specialization into castes. Castes mentioned in the chronicles include Mediators, Engineers, Masters, Warriors, Doctors, Runners, Porters, Farmers, and Meats. All of these castes are in the entourage of a Master. Feral forms have also been observed. Engineers use the semi-intelligent Watchmaker caste (called "miniatures" or "brownies" by the crew of MacArthur) as mobile tools. Where a human can to a greater or lesser degree carry out similar tasks, a Motie of a given specialization performs a single function at a high level with no training.