Supercooling point is correlated with total body water content in a wide range of terrestrial Acari from Antarctic, sub-Antarctic and temperate regions, which have not been cold-hardened by prior exposure to winter low temperatures. This suggests that low water content is itself an important pre-adaptive features conferring considerable cold-hardiness among terrestrial mites. Other physical and behavioural adaptations, for example clearing the gut of potential ice nucleating agents, accumulation of cryoprotectants and behavioural avoidance of low temperatures are considered to be possible secondary adaptations.