How does a rabbit primarily regulate its temperature?

Rabbits primarily regulate their body temperature through their ears, which play a critical role in thermoregulation. The ears are large and vascularized, meaning they have a rich supply of blood vessels. When a rabbit gets too warm, blood flows to the ears where heat can escape into the environment. Conversely, if a rabbit is too cold, the blood vessels in the ears constrict to conserve body heat. This adaptation allows rabbits to manage their internal temperature effectively, especially since they cannot sweat like humans do.

The other options do not play significant roles in thermoregulation for rabbits. While their fur provides some insulation, it primarily helps to keep them warm rather than cool. Similarly, rabbits do not primarily use their feet or nose for temperature regulation, although they may experience slight temperature changes through those areas. Understanding this mechanism is vital for ensuring the health and well-being of a rabbit, especially in varying environmental conditions.