A white sand dust covered bull African elephant (Loxodonta africana) sniffing the air. This photo was taken during a drought in Namibia. Elephants have a keen sense of smell, allowing them to detect water sources up to 19.2 km (12 miles) away. Many animals use chemical communication or pheromones to communicate. They may leave their scent to mark territory or attract mates. African elephants have the largest number of genes dedicated to smell of any mammal.The use of chemical or olfactory cues is central to communication between elephants. Elephants cover their skin in sand dust to protect themselves from the rays of the sun. Photographed in Etosha National Park, Namibia.