Animals

Why do dik-diks have dark marks beside their eyes?

Because special scent glands open there and help dik-diks leave chemical messages. Beside each eye, a dik-dik has a preorbital gland that produces a dark, sticky scent. The antelope presses the gland against twigs and grass, leaving chemical messages. Repeated marks help a pair advertise their territory to other dik-diks moving nearby.