Leafcutter ants are productive farmers with an elaborate society based on ant-fungus mutualism; i.e., a symbiotic relationship between the ant and the fungus. One day last month I had the joy of watching some especially clever ants taking a shortcut.
The ants get safe, underground living accommodations from the fungus, including a means to feed their ant larvae. And in turn, the ants keep the fungus fed and cleaned. Although the ants don’t actually eat from their fungal garden, they chew up the delivered leaves to decompose for the nest.
Many colonies contain approximately one million ants, but there can be as many as 8-10 million ants.
The ants bite off a piece of leaf and carry it back to the fungal garden, their underground nest. This is what we humans see as each ant carries a leaf chunk down the trail. An underground nest can grow to more than 98 feet (30 m) across, with additional chambers leading off of that.
There are many tasks in a community this large, and each individual has a specific role including the queen, several castes of workers, foragers, and soldiers.
Next to humans, they have the largest and most complex animal society on earth.
I’ve seen leafcutter ants in many tropical venues, and always on a forest trail or in grass. They often have a conspicuous trail, because there are so many ants moving back and forth that eventually they wear down the vegetation, as seen here.
One day Athena and I were swimming at the lodge pool, when we noticed little morsels of leaf parading across the floor tiles. There weren’t that many, maybe one ant every foot (.30 meter) or so. I don’t think other people would have even noticed them, but I am always on the lookout for leafcutters, because I think they are one of the most amazing creatures on earth.
The stamina! The industriousness! The tenacity of a leafcutter ant is completely inspiring. Their strength is astounding. They can carry 12-20 times their body weight.
After some investigation, we discovered they were taking a rainforest shortcut through the pool area. They entered at one end of the pool enclosure, walked across the pink floor tiles, and exited at the other end. This was about a 50-60 foot long (15-18 m) trail. They traveled along the floor edge, near the plantings, under the lounge chairs.
There were places where water was on the floor, which upset the parade. A simple small puddle threw off their scent. Here they circled around for a half minute or so, but would then stabilize, get back on track, and eventually find their way to the exit rock.
Each one took the exact same trail, and they all vanished at the same place. The exit rock is in the center of this photo below–there was a gap between the second and third rocks, about the size of a fist.
As the plot thickened, we went outside the pool enclosure, thinking there would be a continued trail. But instead they were gone. They had vanished underground, reached their destination. There we stood in our dripping pool clothes, fascinated.
It was a very hot, humid day; all the birds were resting, all the humans were resting. But the leafcutter ants, they just kept marching.
Written by Jet Eliot.
Photos by Athena Alexander.