0:00

We are beyond the suburbs and the farms in Central Oregon's sagebrush country. It is probably home to coyotes and bobcats. But we are here to observe life on a scale so tiny it is often ignored. There is an entire world under foot, a social system operating here beneath the weeds. This is thatch ant territory. And our miniature camera is exploring one of the many ant trails that radiate like spokes from the primary nest.
The trails are lifelines as the colony collects the food it needs to survive. Our trail is alive with worker ants bearing the trophies of almost endless scavenging.
We must slow the action in order to observe the frenetic scene, and as we do, this ant world under the Central Oregon sage begins to reveal its secrets.
"I think that they're amazing creatures."

1:08

Jim McIver has spent seven years studying thatch ants in Oregon. The word "thatch" pertains to the
straw-mat-like coverings civilizations often use building shelters. In similar fashion, thatch ants construct nests of carefully interweaved twigs. "That nest structure results from the collective behavior of hundreds of workers that are striving to keep that thatch structure up high. So the net result of all their activity will be a movement of thatch from down below to up high."

1:44

A colony is like a living creature and the ants are its moving parts. This is a big colony, a regular ant factory, which will produce 25,000 workers in a year.
The mound breathes as air circulates through the sides and out the top of the nest. But wind and rain and gravity work to flatten and suffocate the structure. Workers struggle to maintain ventilation, constantly tugging the countless twigs back into place.
To fuel this and the other critical demands of survival, the colony has a voracious appetite. "The colony basically needs two types of food and it's sort of analogous to honeybees. Honeybees need pollen and nectar. Ants need protein and honeydew. They need protein and some kind of carbohydrate for energy. And so the economy of the colony is built around collecting these kinds of foods.

2:45

High in the branches of a sage plant, some workers perform a singular food gathering task for the colony.
"Each of the ants has her own clump of aphids that she tends to specialize on and she'll circulate around and harvest honeydew from that group of aphids all day long."

3:08

It is a kind of microcosm of life in this Central Oregon range land near Prineville. The thatch ants tend livestock, minute aphids that infest the sage.
"Antennae of the ants move constantly. They use the antennae to stimulate the rear end of the aphids so that they'll excrete a little bit of a little droplet of honeydew.

3:31

The ants that work the aphids become living storage tanks for the honeydew. Each worker can transport half its weight in honeydew from the sage to the nest. At the nest, the sugary fluid will nourish larvae, young workers and the queen. The honeydew harvester carries the honeydew in a receptacle in the forward part of her abdomen. That natural container is called a "crop." To estimate the honeydew that's stored in her crop we take this capillary tube and put it up against her mouth at the same time as we gently squeeze her abdomen. Honeydew is just like, basically, sugar water. It has about the sugar concentration of orange juice.

4:17

Numberless workers lap up uncounted droplets provided by the aphids, mostly from sunup to dark, collecting enough honeydew to help fuel the colony.
But there is more to the diet requirements of the colony. And the worker ants can be as fierce as any other carnivore. To survive, this colony alone must feed on the carcasses of a half-million insects annually. Several yards from the nest, an injured honeybee has been caught in the ants' unending sweep. Workers cannot easily move so big an object. That problem will be remedied, though, by sharp mandibles and relentless tugging. "They've got it pinioned and it's much too large to transport back. So they'll cut it into pieces. And they'll take the head back by itself. And they'll take the wings off, which they can't eat. And then divide the body up into parts, take those back to the primary nest.

5:18

The ants are excited by the presence of prey or predator. And through some unknown mode, perhaps a chemical or visual cue, the excitement spreads.
The lure of the bee has distracted the ants from our miniature camera. But without the bee, the camera is subject to immediate attack. The aphid tenders, too, are ready to do battle with an alien object like a lens. The worker assumes her classic defense posture, curling her abdomen under and spraying formic acid at the intruder. Any worker will give her life subduing prey or defending against a predator. There is no hierarchy among the ants. There are no leaders. Even the queen, producing eggs deep in the nest, has no authority. "There are no workers that are superior to other workers. There are no foremen. All the workers are basically identical or equal."

6:16

Each spring, the successful colony will generate a new brood of queens and drones that fly off and establish other colonies. And so, by some little understood mechanism, the colony operates year to year. The workers somehow divide the tasks without benefit of a central authority to coordinate the complicated work.
So how they get the work done is probably one of the biggest mysteries. Each individual is programmed with certain information. She's programmed to recognize certain types of communication signals from her sisters and she's programmed to respond to the environment in very basic ways. But a large part of her behavior is also due to her individual experience.

7:11

Jim McIver tags thatch ant workers. He can track them month after month. He feels he has a lot more to learn. "One of the values of studying other living things is finding our own place."

7:25

Careful observation of apparently random behavior may offer more clues to the order of the colony. The mindlessness of the individual somehow yields to a consistent teamwork the colony depends upon for survival.