Ants, though tiny, share a fundamental need with all living organisms: water. Water is crucial for their survival and the functioning of their complex colonies. The ways ants interact with and utilize water reveal fascinating aspects of their biology and behavior.
Why Water is Essential for Ants
Water plays a multifaceted role in the physiological processes of an ant. It is directly involved in digestion, helping to break down food and transport nutrients throughout their small bodies. Water also assists in regulating their internal body temperature, a process important for ectothermic insects. Without sufficient hydration, ants can quickly become dehydrated, leading to reduced activity, lethargy, and even death.
Maintaining proper hydration is also connected to the structural integrity of an ant’s body. Their ability to move and perform tasks depends on their internal fluid balance. A well-hydrated colony is more active, healthier, and better equipped for growth and expansion.
How Ants Find and Drink Water
Ants employ various strategies to locate and consume water in their environment. They can find water in common sources such as dew droplets on plants, small puddles, plant sap, and the moisture within fruits or soil. Their antennae are highly sensitive, allowing them to detect humidity gradients and water vapor in the air.
Once a water source is found, ants drink using specialized mouthparts, primarily the labium, which acts somewhat like a tongue. They can use either a licking or a sucking technique, depending on the species and the viscosity of the liquid. They often store collected liquids in a specialized foregut called the crop, also known as a “social stomach.” This stored liquid is then shared with other colony members, including the queen and larvae, through a process called trophallaxis, where ants regurgitate fluids mouth-to-mouth. This communal sharing ensures that water circulates throughout the entire colony.
The Drowning Risk
Despite their reliance on water, it also presents a significant danger to ants, primarily due to surface tension. For creatures of their small size, the cohesive forces between water molecules create a strong surface “skin” that can trap them. An ant’s body is water-repellent due to a waxy cuticle, but their legs can become entrapped in the water’s adhesive forces, making it difficult to escape a droplet or puddle.
Ants have developed adaptations to mitigate this risk. Their light weight, combined with their water-repellent exoskeletons, allows many species to float on the water’s surface. Some ants can close their spiracles, their breathing holes, to prevent water from entering their respiratory system, allowing them to survive submersion for extended periods. Furthermore, black imported fire ants have been observed using sand grains to build structures that effectively siphon liquid out of containers to avoid drowning while still accessing water.