The ears do two clever jobs. First, they help the fox hear tiny noises - like a beetle moving under the sand. Second, they act like radiators that let extra heat escape, so the fox stays cool in the desert sun.
Fennec foxes are most active at night, when the desert is cooler. During the day, they sleep in burrows they dig deep into the sand. A burrow can have several entrances so the fox can always run home a different way if a bigger animal is chasing it.
They are great jumpers. From a standing start, a fennec fox can leap about a metre into the air - useful for catching insects mid-flight. They eat insects, small lizards, eggs, fruit and roots, and they can survive for a long time on the water they get from food alone.
Even their feet are designed for the desert. The bottoms of their paws are covered in thick fur, which protects them from hot sand the way slippers protect your feet from a hot bathroom floor.