The ears, which represent about 12% of the body surface, also have a thermoregulatory function. The ears have a widespread network of blood vessels that can constrict or dilate to conserve or dissipate heat. At high temperatures the ears, which are lightly covered with hair on the outside and completely hairless on the inside, become red and very hot (due to increased blood flow) and this allows them to dissipate more body heat than any other part of the body (remember that rabbits do not have sweat glands). If the goal is heat dispersion, the ears are placed laterally to the body, while at low temperatures (below 15°C), in order not to disperse heat the ears are extended as close as possible to the body, along the back.