Heavy rains pose a risk of drowning or destruction of ant colonies, in addition to the disorientation of ants as their pheromones trails are wiped out from the ground, so they devise strategies to ensure safety.
How Do Ants Prevent Flooding? Ants can prevent flooding by forming floating rafts, drinking rainwater, closing breathing pores, collecting twigs and soil around colonies, blocking entry holes with stones, moving to safe places or deep into tunnels, building dome-shaped nests, and building underground air chambers.
Light rains do not interfere in the ants’ nest as these make the soil slightly wet, but heavy rains can lead to flooding of their nests and destruction of chambers.
Formation of floating rafts
One of the most prominent defensive strategies against flooding is the formation of floating rafts, commonly observed in fire ants.
Collective colony efforts can form a raft when hundreds or thousands of these insects get tightly attached to each other to increase the overall mass and surface area.
Every ant grasps the legs of another fellow and makes a large pile where each member remains connected to more than one insect at one time and builds a living raft.
Accordingly, they can remain floating for many days and keep walking on the rainwater surface. These rafts are formed by workers that usually grasp queens and keep them in the center.
Furthermore, this raft-like structure disintegrates when they escape floods or reaches a dry place. This type of behavior is found in fire ants, while other species follow different strategies.
Some ant species have a strategy of communal peeing to protect themselves against flooding when there is water everywhere within the ant colony.
All colony members of bamboo ants drink water as much as possible and get it out of their nests to release it from their bodies.
This is referred to the communal peeing because massive efforts are required from the whole colony to remove water from their nests made of bamboo.
Furthermore, this behavior of insects allows them to avoid the risk of flooding to some extent because a large number of insects are involved in communal peeing.
Close breathing pores
Ants have spiracles or breathing pores on their bodies, allowing oxygen exchange between atmospheric air and their body tissues.
These spiracles are connected to tracheal tubes, which transport oxygen to the body tissues and bathe internal cells with oxygen for metabolism.
Moreover, these insects can keep oxygen stored within the tubes to survive in conditions when there is no availability of oxygen to them.
Accordingly, these insects close their breathing pores quickly when there are flooding conditions and rely on stored oxygen. It helps avoid water entry into their bodies and helps them survive.
Build walls around the ant colony
Some species of ants build walls around their nests, protecting their mounds from flooding and keeping water away from their nests.
They collect plant twigs and make a pile around their mound for added protection because it is challenging to collect bigger rocks or heavy stones to make hard walls.
Moreover, these twigs strengthen their underground homes and restrict flowing water to some extent. In the same way, they build a barrier by collecting soil and making piles around the nest.
Collecting the soil particles and building walls around the mounds takes a lot of effort. This is because the rainwater seeps through piles of soil and keeps flooding water away from their nests.
Plugging holes with objects
Every mound has one hole that is used as a route for the entry and exit of ants when they have to go foraging and bring food particles back to the nest.
This entryway can also provide a route to water and causes flooding of nests during heavy rains. Accordingly, these insects stuff stones in this hole to block the route for water runoff.
This entry point is usually close to the top of the anthill that gets covered with water. Blocking the hole with stones works well to control water flow inside tunnels.
Furthermore, many colonies have soldier ants with bigger heads that protect the nest and nest members.
So, they block entry holes using their bigger heads, intending to protect a colony from flooding and avoid the risk of being drowned in rainwater.
Dig deeper or evacuate tunnels
Some species of ants dig deep tunnels in the underground nests by continuously moving deeper into the soil and reaching around 20 to 25 feet depth.
These deeper tunnels can protect them during heavy rains when there is a risk of flooding because they can hide deep inside the intricate channels runoff water cannot reach.
These ants do not like to remain on the open grounds during rain as they dig deeper into the soil or sneak through narrow spaces to reach indoor areas.
In addition, these insects can predict rains and begin to evacuate their nests when they detect a risk of flooding. They find suitable places indoors to get moisture, food, and warmth.
Most commonly, they hide behind walls, baseboards, attics, wooden floors, cracked tiles, and even wooden furniture, providing a safe spot to spend some time.
However, some of them choose trees with a bigger canopy to get shelter and climb the trees to live there until the rain stops and the ground gets dry.
Form underground air chambers
Some species of ants spend most of their lives submerged in mangroves, commonly found on the Australian coastline. However, they have the risk of attack by fish, so they build mud mounds.
These insects have adapted themselves according to environmental challenges and built strategies to prevent flooding and collect air by creating air pockets within nests.
Moreover, Polyrhachis Sokolova makes muddy mounds when there are low tides and forms air chambers under the ground.
These air chambers provide oxygen to insects when they feel suffocated. They collect food and fill air chambers with more oxygen during lower tides.
Build dome-shape muddy nests
Ants build nests with a unique design and internal structure, allowing them to resist damage against flooding. They build a dome-shaped anthill that allows water to run off on the ground.
The rainwater falls directly on the top of their nest and runs down towards the ground surface.
The cone shape of their mound repels water away and keeps them dry until it gets covered with water.
These insects are smart enough to build internal drains providing a passage to water to flow out, which can help protect them in heavy rains and avoid flooding of nests.
The rainwater moves out of the drain holes without causing much disturbance in the other living chambers filled with larvae, pupae, queen, and male ants.
Moreover, they use a mixture of sand and soil to build their nests, adding extra strength to their nests because they can absorb water and prevent flooding.