* To avoid the heat: The Sahara Desert, where fennec foxes live, gets incredibly hot during the day. Their small size and large ears make them particularly susceptible to overheating. By being nocturnal, they can avoid the hottest part of the day and hunt and forage when it's cooler.
* To hunt prey: Many of their prey animals, like insects and rodents, are also nocturnal. Being active at the same time as their prey gives them a hunting advantage.
* To avoid predators: Larger predators like foxes, jackals, and eagles are active during the day. Being nocturnal reduces their risk of being hunted by these predators.
The large, prominent ears of fennec foxes also play a role in their nocturnal lifestyle. Their ears help them dissipate heat and are extremely sensitive to sound, allowing them to hear prey moving in the sand even from a distance.