A Kirk’s dik-dik darts, pursued by a swarm of flies!
If you’ve ever seen a Kirk’s dik-dik (Madoqua kirkii)—one of the world’s smallest antelopes—standing still while swarmed by flies, you’ve likely felt a wave of sympathy. These adorable creatures appear tormented (and likely are!), but there is a fascinating biological reason for the bug-eyed drama.
It’s All in the “Tears”
The flies aren't just annoying the dik-dik for fun; they’re after the preorbital glands* located just below its eyes. These glands produce a dark, sticky fluid—with pheromones—used for marking territory. Dik-diks are very territorial; they rub this fluid on twigs to leave a “keep out” scent for others. This fluid is protein-rich and therefore an irresistible snack for flies in the dry savanna.
Close-up of flies and a dik-dik antelope, showing the black preorbital gland below the eye and its twitching snout.
so How Do They Cope?
Despite the swarms, dik-diks have some defenses against flies (and other more potent threats):
The Nose Wiggle: Their twitching, trunk-like snouts help deter flies from landing (and incidentally, help them sniff out the territorial markings of others).
Mutual Grooming: Since they mate for life, pairs often lick away secretions—and flies—from each other’s faces.
The Freeze: As natural “hiders,” they stay perfectly still to avoid predators, although going “statue mode” makes them easy targets for insects.
So the next time you see a fly-covered Kirk’s dik-dik, remember: it’s just the price they pay for being the most dedicated scent-markers on the African savanna.
*Those preorbital glands are known as a vomeronasal organ (VNO) or Jacobson's organ. Unlike most mammals that also have developed VNOs, Old World monkeys, apes, many bat species, and humans have a VNO duct, but lack the “wiring” to make them functional! And just in case you are privately exploring your nose right now, realize that it is located in the lower third of the nasal septum, but is microscopic in most people.
One more thing. If you want to read more about this wondrously specialized antelope, see our post: “Kirk's Dik-Dik: A Tiny Antelope with a Special Snout.”