Subterranean royalty: All hail the king

While millions of eyes were on the coronation of Charles III this weekend, other male monarchs will carry on ruling in obscurity — literal obscurity, because they live in darkness underground, or maybe in a piece of rotting wood. Queens are familiar figures among insect species. But it is only in termites that royal families include kings. Long-lived, ensconced in fortified royal chambers and faithful to their enormous queens, these rulers are unique in the insect realm. “There are some parallels to our monarchy system for humans,” said Barbara Thorne, a termite biologist and professor emerita at the University of Maryland.

Termites, like many ant, bee and wasp species, live in collaboratives of sterile workers. But there are crucial differences. In the nests of ants, bees or wasps, the sole monarch is a queen. She stores all the sperm she will need for the rest of her life after a single, eventful mating flight. She uses the stored sperm to produce daughters, who take on all the work of finding food and caring for their younger siblings.

Termites evolved separately from these other insects, and they do things their own way. For starters, both a queen and a king are needed to start a termite colony. The reason isn’t romantic: Female termites can’t store sperm, so they need a male to inseminate them over and over. A study of one species found that it happened daily.

King and queen work together to get their family started. The male “helps with every aspect of it,” Dr. Thorne said, “from the brood care to nurturing, feeding, providing water, attending his queen.”

Soon, though, the royal couple steps back. They keep making babies, but let grown offspring handle the forage and child care. Those helpful kids are both male and female, a society of brothers and sisters working together. Some also grow up to become soldiers specially built for defending their colonies.

The queen and king don’t set themselves apart with crowns or other regalia, but they do start out in adulthood with wings, which they shed as they’re settling down. The queen becomes “ginormous, just a big sac of ovaries, basically,” said Ed Vargo, an entomologist at Texas A&M University. The king, while dwarfed by his bride, is still larger than the workers, and usually the soldiers.

Termites can’t see those differences, as they live in the dark. But Dr. Vargo’s lab has shown that workers and soldiers can recognize their sovereigns by smell. When another termite is near a queen or a king, it shakes its body, perhaps alerting others that they’re in the presence of royalty.

And although they don’t have a castle, Dr. Thorne said, “They do have a special royal cell with a little chamber that’s primarily the queen and king.” Deep within the nest and with thicker walls, this chamber protects the queen and the king if, say, an anteater takes a swipe.

As the royals don’t leave their chamber, workers give them regurgitated food from their own mouths. Other colony-living insects spike their mouth-to-mouth meals with chemicals for communication, Dr. Vargo said. It’s possible that termites do the same thing. For now, though, the makeup of these termite meals is as mysterious as the “secret mixture of oils” with which Charles III will be anointed, using the centuries-old coronation spoon.