This photograph shows a nest of a harvester ant in India. The area where this nest is found in the Western Ghats experiences 3 to 11 meters (9 to 36 feet) of rain during a monsoon season that lasts three to four months. Rainfall like that could be devastating for the ants’ underground brood chambers and fungal gardens.
The nest’s architecture likely functions to divert large amounts of water from the central nest entrance. The ants build these nests on a slant and the spiraling channels guide the water away, slowing it down rather than risk eroding the face of the nest. There are no ants in this photo, but based on another photo we’ve seen, about five ants of this species would fit on the person’s fingernail.
Notice we said “likely functions.” What do you think? Here’s an activity you can do to test this idea: Using mud or clay, create a structure that looks like this one (or look for other photos on Google Images). Then experiment with different levels of “rainfall.” What happens with a sudden downpour? Where does the water go? How much water can the structure manage? Is there anything we can learn from ants by studying this structure?