Ants possess remarkable abilities to survive in aquatic environments, showcasing a resilience that allows them to endure. Their survival tactics involve a combination of individual physiological adaptations and collective behaviors. These adaptations enable them to persist in conditions that would be challenging for many other terrestrial insects.
Individual Survival Mechanisms
Individual ants are equipped with several physical and physiological adaptations that allow them to survive when submerged in water. Their outer covering, the exoskeleton, is naturally hydrophobic due to a waxy coating and fine, water-repellent hairs. This waxy layer prevents water from adhering to their bodies, causing water droplets to bead up on their surface.
Ants do not possess lungs like mammals; instead, they breathe through a system of tiny openings called spiracles located along their bodies. When submerged, ants can close these spiracles, effectively holding their breath and preventing water from entering their respiratory system. Additionally, the hydrophobic hairs on their bodies can trap a thin layer of air, known as a plastron layer, when they are underwater. This trapped air bubble provides buoyancy and can function as a temporary “physical gill,” allowing for limited oxygen exchange with the surrounding water.
How Long Ants Can Survive
While ants exhibit impressive water survival capabilities, their endurance is not limitless. The duration an individual ant can survive underwater varies significantly depending on the species and environmental conditions, ranging from about 24 hours to up to 14 days. Some species, like carpenter ants, have been observed to survive for the longer end of this spectrum.
The primary limiting factor for an ant’s underwater survival is the eventual depletion of oxygen within its trapped air bubble and the subsequent buildup of carbon dioxide. Environmental factors also influence survival time, including water temperature, with lower temperatures generally allowing for longer survival periods. The ant’s metabolic rate plays a role; ants can enter a torpor-like state, reducing their oxygen consumption and extending their survival time when submerged.
Collective Ant Raft Formation
Beyond individual survival, many ant species, particularly fire ants, exhibit a collective strategy to survive floods by forming living rafts. When their underground nests are inundated, ants rapidly link their bodies together using their legs and mandibles. This cooperative behavior results in a multi-layered, interwoven structure that floats on the water’s surface. The collective hydrophobic properties of thousands of ant exoskeletons create a buoyant and water-repellent barrier, effectively forming a “waterproof fabric.”
Within these living rafts, the colony’s queen and vulnerable larvae are typically protected within the raft’s core, shielded from the water. The trapped air pockets within the interwoven ant bodies enhance the raft’s buoyancy and allow ants in the lower layers to breathe. These self-assembling rafts are a social behavior for colony survival, enabling the entire colony to float for extended periods, sometimes weeks or even months, until they can find dry land. Some fire ant rafts have been observed to survive afloat for up to 12 days. This collective action allows for the dispersal and continuation of the colony in adverse conditions.