Apparently there really is such a thing as an “ant farm.” Yes, there was a toy called an “ant farm,” that was popular a couple decades ago but new research actually suggests that Fijian ants were planting fruit crops long before humans started to.
As a matter of fact, the University of Munich, Germany, research team claim that these insects were doing it millions of years before ancient humans. Reconstructing the evolutionary history between Fijian ants and fruit plants they were able to discern a symbiotic relationship.
According to professor Susanne Renner and research student Guillaume Chomicki, Fijian ants may have actually started to cultivate fruit plants more than 3 million years ago. Apparently, colonies of the Philidris nagasau Fijian ant actually grow and harvest epiphytes that grow harmlessly on another tree. These epiphytes can include Squamellaria fruit plants which commonly grow on branches. They are, essentially, endemic to Fiji.
The researchers explain that Fijian ants will first gather seeds from the Squamellaria fruit and then look for cracks in the bark of the host tree they have chosen. If and when they find a fissure, the ant will actually plant the seed inside the space. Of course, the seed will then germinate, with worker ants watching over the planting sites (maybe even fertilizing the sites with their own feces). The plant will then, indeed, grow and form large and round hollow structures at the base—these are known as domatia—where the ants will then live instead of building a nest. Once the fruit appears, the Fijian ants will eat them and then collect the seeds to use for a future harvest.
And the cycle begins again.
And Chomicki explains that every plant they checked, sure enough, had ants living it them. And they also found that the ants do not venture to other plants; suggesting a symbiotic relationship (otherwise the ants would just lounge at whatever plant is convenient).
“The story is unique,” explains California Acadmey of Sciences entomologist-in-residence Brian Fisher. “We already have ants that disperse seeds, and have ants that feed plants, but we’ve never had a case where they farm a plant they can’t live without.” He also adds that roughly 40 percent of annual plants located in the Northeastern United States are dispersed by ants.