Crematogaster ashmeadi

School of Ants collection
Literature record

Crematogaster ashmeadi

From Dr. Eleanor's Book of Common Ants

Species name: Crematogaster ashmeidi, Crematogaster lineolata, and Crematogaster cerasi

A.K.A.: Acrobat ants

Size: 0.1-0.18 inches

Where it lives: Most often, you will find acrobat ants nesting under bark in trees, the forest floor, or rotting wood, but sometimes they wander into our homes, snuggling their nests in tight spots like between shingles and in the walls.

What it eats: Primarily sugar lovers, acrobat ants sometimes take a break from lapping honeydew off aphids’ rear ends to forage on protein like dead insects.

What’s the big deal?

One summer, I traveled to a remote North Carolina island for a research project. The project required that I crawl under and around people’s homes looking for ants.

While walking to one home, I accumulated a following of local ducks that waddled behind me waggling their bills in hopes of food and quacking reproachfully when they found none. I hate to disappoint, so I snuck into a local’s backyard and dumped out my supplies, looking for a duck-suitable snack. As I rifled through my bug-collecting equipment, a man came out of the house.

“Hello, ducks ducks ducks!” he said, and the ducks happily abandoned me for their old friend. Thinking I was caught trespassing, I shoved my equipment back in my bucket and hurried to introduce the man to this potential thief/weirdo lurking around his backyard. He told me he could hear me coming but couldn’t see me; he was blind.

”I’m looking for ants,” I explained.

“Ants?” he asked, “I’ve got acrobat ants! Come see!”

The ducks and I followed him. He felt the way off his back porch, running his rough hands along the brick walls of his house, around the corner, and pushed his body behind a hedge. He pulled back branches from a wax myrtle tree and revealed a pipe leading into his house. On that pipe? A parade of acrobat ants, their little heart-shaped fannies waving in the sun!

I tried to imagine how he could find this tiny treasure so deeply hidden.

“How in the world could you tell these were acrobat ants?” I asked.

“Because,” he said, and he slammed his hand down on the pipe, smashing a couple of workers. When he lifted his hand, I watched the stunned workers stumble about, smoothing their crumpled legs and antennae, gradually going back to work. “You just can’t squish the jimdurn things.”

He was right; acrobat ants seem to defy squishing.

Acrobat ants are a gift, a joy, and you can find them almost anywhere you’d imagine in the United States, from swamps and forests (i.e. Szalanski et al. 2010) to your kitchen cabinet (i.e. Scharf et al. 2004). Three species of acrobat ants make the most common U.S. ant species list: Crematogaster ashmeidi, Crematogaster lineolata, and Crematogaster cerasi. These species can be hard to tell apart just by looking at them. About the size of an apple seed, they range in color from rusty bodies with dark brown/black abdomens to a deep reddish-black all over.

Even so, you can tell acrobat ants from other types of ants by their heart-shaped bottoms, or gasters. They trail in happy lines to and from food. When disturbed, acrobat ants halt and wave these hearts in the air like proud flag bearers in a pageant.

It’s hard to imagine how acrobat ants are among the most abundant ants in forests and homes (Szalanski et al. 2010), considering how fragile colony-founding goes for them. Imagine the big forest where acrobat ants might live. Picture all the towering trees, with their seemingly infinite number of branches, stems and leaves, jutting out against the sky. Now picture one tiny ant, a newly mated queen, a slightly bigger apple seed, embarking alone for the journey of her life.

All kinds of animals like spiders, mice, beetles and birds would love to snack on our queen, and the forest trembles with life as these predators peek and poke about, looking for a treat. Our queen, our apple seed, keeps her course, searching the branches for an abandoned beetle or termite gallery to make her new home. When she finds one, she settles in, laying eggs that will become her empire (Tschinkel and Hess 1999; Hahn and Tschinkel 1997; Baldacci and Tschinkel 1999).

For every 100 acrobat ant queens that journey to find a new home, less than eight survive to form a colony (Hahn and Tschinkel 1997). Once formed, the colony can live 10 to 15 years and may have from a few to several thousand workers crawling across the branches, eating everything from nectar to other insects.

Those workers help keep forests healthy and balanced. Acrobat ants help protect or sustain at least two endangered species: the Miami blue butterfly (Saarinin and Daniels 2006) and the red cockaded woodpecker (Hess and James 1998). In exchange for a sweet substance produced by Miami blue caterpillars, acrobat ants feistily fend off would-be butterfly poachers like birds and other ants. They also are the red cockaded woodpecker’s primary diet. Wiping out acrobat ants could have a domino effect across the forest with other species falling down behind them.

Consummate hosts, acrobat ants often harvest clytrine leaf beetle eggs from leaves and, without eating them, bring them into their nests, where the eggs hatch in a predator-free environment (Stiefel and Margolies 1998). Another ant-loving beetle Fustiger knausii spends most of its life hanging out in acrobat ant nests, relaxing with the brood and riding around on workers’ backs (Leschen 1991). They groom the ants and might get food by enticing workers to spit up snacks for them to eat!

Like my duck-loving friend on the island, you’ll find acrobat ants parading around your kitchen or, true to their name, tightroping across your clothesline. Don’t be afraid of them! They aren’t dirty and they won’t hurt you. Many of us commonly encounter acrobat ants and don’t realize it. That’s because unlike my friend, many of us choose to be blind, to ignore these marvels of life as they shiver all around us. Maybe, like my friend, you can take a break to experience the pageantry of the happy procession before you. To enjoy the sensation of those cheery bottoms waving in the air on their way to work. To thank them for the job they do. Just try not to squish them.

Find out more about this species at Antweb and see more photos at Alex Wild's photography site.