A generation ago, the hopes for a colony on the moon or elsewhere beyond the Earth’s atmosphere were great, so great that a replica of what such a colony might look like was built on Earth. The replica was called Biosphere 2 and its aim was to figure out if an entire ecosystem could be built from scratch. Its goal was to be a terrarium inside of which humans could be a focal species, observed and sustained.

The humans who crawled inside Biosphere 2 did not last long. Oxygen was in short supply. Many other things went wrong. And then came the ants.

Ants have taken over Biosphere 2 to an extent unprecedented even among the most invaded habitats outside of that realm. They have proven that societies could live in a fabricated from scratch ecosystem in space, just not ours.

I was put to think about all of this recently when, I saw on Facebook (picture re-posted above), that Clint Penick, in my lab, and Eleanor Spicer Rice, in my neighborhood, had worked with Stefanie Countryman and BioServe Space Technologies to send ants to the International Space Station (ISS).

The ISS is as close as we have ever come to building Biosphere 2. The Space Station does not really have plants. It is a biosphere composed entirely of the astronauts and the thousands of species living on them. These species include mites, astronaut face mites. They include gut bacteria, belly button bacteria, armpit bacteria, and whatever else, be it worm or louse, that happens to have hitched a ride. And now there are the ants.

Clint and Eleanor collected pavement ants (Tetramorium spE) to send to the Space Station. They sent along a relatively large colony, 800 individuals. The ants rode in a small container up to the station where they now float around inside that same container. It is hard to avoid worrying about ants taking over the ISS. They haven’t yet, but they have the possibility. They are one of the species best able to persist under tough conditions; pavement is their preferred wilderness after all. But there is already something else to note.

Humans have never established a colony in space. It seems much further off today than it might have a few decades ago. No babies have been born in space. There is no lunar Virginia Dare. But this is not to say that civilizations have not established themselves outside of our solar system because, as should now be clear, inside a small container on the space station there is, right now, a colony of pavement ants. There are workers. There are even the guests of the ants, their microbes and who knows what else. Fungi? Yes. Worms? Probably. Springtails? Maybe. The ants, in other words, have, just as in Biosphere 2, done what we have been unable to do.

The ants are in space to provide a measure of just what happens to ants without gravity. There are easier ways to measure this effect, but the space version is more compelling. It is also, probably, our best real shot at a long-term space colony. All that has to happen is for those ants to escape. Surely, they will try. Then the question will be whether or not they will be able to gather the astronauts’ crumbs as they float by.