Different species of ants have different coping mechanisms for surviving the rain.
Some, like Army Ants, carry on as if the rain isn’t affecting them. Others create complex anthills designed to cope with flooding. And bamboo ants solve the problem through a process called ‘communal peeing’!
Overall, rain doesn’t pose much of a threat to ants because they’ve evolved and worked as cohesive hard-working colonies to find solutions to rain flooding their anthills.
How Ants Survive the Rain
1. Digging Deep
Rain doesn’t penetrate too deep into the soil. Some species of ant take advantage of this by digging their anthills very deep.
The deepest anthill is that of the leaf cutter ant which can be as deep as 26 feet. For these ants, a heavy rainfall may cause damage to the upper chambers of the anthill, but the water is unlikely to get too deep through the chambers.
Once the storm has cleared, the ants can build replacement chambers and pathways out of the mound to continue with their daily work.
2. Complex Anthills
Ants in anthills are usually pretty well protected. Their homes are made up of a complex network of chambers and passageways that prevent rain from penetrating deep into the nest.
Water may penetrate the top few chambers, but with each chamber, the anthill can catch and dam up the water and prevent it from getting deeper.
Because the paths between chambers are so thin, the water will often reach a bottleneck and cause blockages and clogging, which protects the chambers below.
3. Plugging Holes
Some ants will block the entrances to their anthills when rain is coming.
This can include placing rocks, sticks, and stones on the entrances. However, usually an anthill has many hundreds of entry points, meaning this process isn’t fully effective.
While the leaf cutter ant can build very deep nests, other species only build very shallow ones. For these ants, sometimes it’s best to simply make an escape.
They can be seen carrying tiny white things that are larvae of their young. They will take these larvae up hills, tree trunks, rocks, or higher ground to keep the larvae dry.
Once the rain clears, they can bring these larvae back into the nest and find a chamber that is dry and safe.
5. Air Chambers
There is even a breed of ant that lives in submerged mangroves in Northern Australia. The Polyrhachis sokolova species make mud nests during low tide to create underground air chambers.
These ants will emerge from their nests during low tide to scavenge along the shores of the mangroves for food that has been washed up in the recent tide.
As the tide rises, they retreat back into their nests. The nests are designed with special air chambers so they can survive the flood during each tide.
Scientists even believe that these ants can swim if they need to escape their nest.
Of course, they’re also exposed to a unique range of predators, including fish, mudskippers, and crabs.
During heavy rainfall or floods, some anthill chambers may be completely flooded. In these cases the ants will be forced to leave their home.
Water entering the tunnel as a result of heavy rain usually does not travel far. The ants dig holes at least a foot deep (and up to 26 feet deep for some species). They have a complex tunnel system that works in a similar way to storm drains. Water will flow through the nest without much disturbance to the main living quarters as long as the rainfall isn’t too heavy.
6. Build a Raft
Some ants, such as the fire ants (Solenopsis invicta), have the unique ability to build rafts on the surface of rising water using their own bodies rather than scattering separately. The rest of the colony swirls “comfortably” on a layer of ants at the bottom of the raft.
The rainwater cannot penetrate the raft due to the tight weaving of the ants, which keeps them dry. The water tightness of the raft gives it the buoyancy it needs to float.
If necessary, the ants can remain on the raft for several weeks or until the rain waters recede and they can move their colony to a new underground home.
7. Communal Peeing
Yep, you read that right. Bamboo ants (Cataulacus muticus) will drink the water entering their bamboo nests, run outside, and pee it off the edge!
This is a mighty effort. But there are many, many ants in a nest. And when all the ants get to work, they can hold off a flood in their bamboo nests by collectively drinking the water than peeing it out.
This massive effort has gotten the name: “communal peeing”.
1. Do Ants Die in the Rain?
Generally, ants can tolerate rain, and they will survive for sunny days ahead.
Ants make their nest durable and resistant to invaders, including rain. Their homes act as fortresses to protect the colony, but most importantly, they prevent the queen from being killed.
Nests are usually designed specifically to protect the queen ant and larvae, which are both buried deeply into a chamber in the nest.
Even the outside shape of an anthill can help prevent flooding. The cone shape pushes water away from the ant nest and down the sides of the anthill.
2. Which Ant Species is Most Adapted to Survive in Rain?
Fire ants and some Mangrove ants are the most adapted to survive in the rain.
Even if ants are caught outside in the rain, they have a chance to fight. Ants can walk on water because they are too light to break the surface tension.
When carried away in the rain, fire ants have a habit of clinging together to form rafts.
Ants can also use smart architecture to survive in areas with high flood risk. Perhaps the most important defense from rains is Bamboo Ants (Cataulacus muticus). As its name implies, bamboo ants create their nests on the branches of bamboo that might flood after heavy rain.
Related: Do Ants Drown in Water?
Ants have developed ingenious ways to avoid and survive the rain. But different species have different mechanisms. Generally, most ants can simply survive deep within their anthills until the rain passes. But others have great skills in creating rafts and even ‘communal peeing’.
Ants have complex and intelligent ways to work as a team to evade the rain. As with so many other aspects of their existence, ants adapt and work as a cohesive, hard-working colony, to overcome adversity.