Labor Day Ant: Tiny Critter with a Big Impact

With Labor Day just passing and unofficially ending summer, my thoughts turned in a weird direction-- to a creature named for the holiday, if you can believe it.

It's the Labor Day ant, named for when its mating swarms are likely seen. Few of us can identify many (if any) ants by name-- “oh, that's an ant” is the best we can do-- this one is so ubiquitous that you’ve seen millions of them in your lifetime without knowing it. And you can now give it its proper name.

Ant expert and noted author Edward O. Wilson, the gentleman scientist who coined the word “biodiversity”-- called it “one of the most abundant and conspicuous insects” in the Northeast, nesting alongside sidewalks and on grassy median strips, lawns, and even farm fields. A creature of disturbed soils, which urban and suburban areas excel in creating, this ant is thriving. Likely only a few steps outside your front door

Small brown ants that eat a wide variety of foods, Labor Day ants consume many other insects, dragging their dead bodies underground to share with nest mates. They’ll also farm aphids, a remarkable relationship between two insect species that happens across both ant and aphid worlds. Aphids, those very small insects that suck plant juices from a wide variety of plants, excrete a sweet waste product from their abdomen nicknamed “honeydew,” which many other insects love. (You may find your car windshield covered in honeydew-- aphid poop-- after you park under a tree in the summer.)

Labor Day ants specialize in caring for aphids that feed on roots, protecting them from other insects while raising their nymphs in special chambers in their nests. When a queen leaves a nest to start a new colony, she may even carry an aphid along with her to start a new aphid colony in her new nest.

When a colony is large enough, often in late August or early September, thousands of winged males and winged queens ascend into the air at once. “One year,” noted Isa Betancourt, entomologist at the Academy of Natural Sciences and one of the consultants helping with my book Wild Philly, “there was a huge emergence of kings and queens in Philadelphia, so much so that it made local TV news, and people hosting Labor Day weekend parties were actually upset as the ants were flying through their parties.”

Once mated, the drones-- kings-- die, their work done, and the queens bite their own wings off and start working on a new colony underground. “One time while I was doing a live broadcast on my podcast,” Isa continued, “I found a winged queen and held it in my hand to show everyone on video. It bit its wings off right in my palm-- snip! snip!-- which was really cool to show everyone.”

The ant is one of the first of its kind to appear in newly disturbed soil. Their tunneling effectively greatly increases both soil respiration and local biodiversity; this action encourages other insects to move in, which brings additional plants and animals.

Ants are among the most numerous animals on earth, as a recent study estimated that Earth is home to 20 quadrillion ants-- that’s a whopping 20,000 trillion individual creatures! They clean the forest floor of dead plants and animals, grow fungi underground, plant billions of seeds, aerate the soil with their underground tunnels, and so much more.

They are easily one of the small creatures holding up the entire planet. “ If all humans disappeared today,” Canadian scientist, TV personality, and activist David Suzuki wrote, “the earth would start improving tomorrow. If all the ants disappeared today, the earth would start dying tomorrow.

So look for swarms of small brown ants on sidewalks and in fields about now, and say hello to the Labor Day ant, busy holding up the world.

And happy fall.