Does hair on a fennec ear protect it from hot desert sand?

While fennec foxes do have fur covering their ears, it's not the primary protection against hot desert sand.

Here's why:

* Large ear surface area: The most important factor for heat dissipation in fennecs is the huge surface area of their ears. This allows them to radiate heat away from their bodies very efficiently.

* Blood vessels: Their ears are also richly supplied with blood vessels, which allow for efficient heat exchange.

* Fur: The fur on their ears likely serves a secondary purpose. It may help to reflect some sunlight and provide a slight insulating layer against extreme temperatures.

In conclusion: The fur on a fennec fox's ears is not the main defense against hot sand. It's their large ear size and efficient blood circulation that allow them to stay cool in the desert heat.