The world is home to approximately 20 quadrillion individual ants, making them one of the most numerous and widespread organisms on the planet. Their total dry biomass is roughly 12 megatons of carbon, surpassing the combined mass of all wild birds and wild mammals. Ants are a dominant insect group found in nearly every terrestrial ecosystem, from tropical rainforests to arid grasslands. Considering their sheer scale and ubiquitous presence, the vanishing of every ant on Earth would trigger an immediate and profound ecological collapse, fundamentally altering biological processes across the globe.
Changes to Soil Health and Structure
The constant movement of ants beneath the surface establishes them as industrious ecosystem engineers. Their tunneling and nest-building activities physically transform the soil matrix, a process known as bioturbation. This subterranean construction significantly increases soil porosity, creating channels that facilitate the flow of air and water. Improved soil aeration is beneficial for plant root respiration and enhances the activity of beneficial soil microorganisms.
Ant nests also improve the soil’s hydrological properties by increasing water infiltration and reducing surface runoff. As they excavate and forage, ants transport and redistribute fine soil particles and organic matter from the surface to deeper underground chambers. This action moves essential nutrients, such as nitrogen and phosphorus, deeper into the soil profile where they become more accessible to plant roots. Ant activity can result in a measurable enrichment of nitrogen content in surrounding nest soil, contributing to overall soil fertility and long-term ecosystem health.
The End of Seed Dispersal
A vast array of flora relies on ants for seed dispersal, a mechanism known as myrmecochory. This mutualistic relationship is driven by an elaiosome, a specialized, lipid- and protein-rich appendage on the seed. The elaiosome acts as a food reward, attracting foraging ants to carry the entire seed package back to their colony.
Inside the nest, ants consume the elaiosome, leaving the seed undamaged. The intact seed is then discarded into a nutrient-rich waste chamber or midden near the nest. This location offers protection from seed predators and provides a fertilized substrate for germination. Without this dispersal service, hundreds of plant species, including temperate woodland wildflowers like trilliums, violets, and wild ginger, would suffer a decline. Their seeds would drop at the base of the parent plant, failing to colonize new areas and leading to reduced genetic diversity and localized extinctions.
Uncontrolled Insect Populations
The most immediate consequence of ant removal would be a surge in the populations of other arthropods that ants regulate as generalist predators and scavengers. Ants are efficient hunters of other insects, their eggs, larvae, and pupae, providing a continuous biological control service in natural and agricultural systems. The absence of this predatory pressure would release many herbivorous insects from their primary natural constraint.
A population explosion of agricultural pests, such as caterpillars, flies, and certain beetles, would lead to extensive crop damage and significant losses in food production globally. This regulatory void would also impact public health through the unchecked proliferation of insect disease vectors. For instance, the presence of red wood ants is negatively correlated with the abundance of Ixodes ticks, which transmit Lyme disease. Ants are also effective regulators of Aedes mosquitoes, vectors for dengue and Zika virus, with foraging ants capable of removing their eggs in experimental habitats. The removal of ants would result in a widespread increase in vector-borne disease transmission and a global health crisis.
Impact on Ant-Dependent Predators
The sudden loss of ant biomass would initiate a severe trophic cascade, directly impacting specialized predators known as myrmecophages. These animals have evolved adaptations that make them obligate or near-obligate ant-eaters. Specialized mammals, such as the Giant Anteater, Silky Anteater, and Tamanduas of the Americas, along with pangolins, aardvarks, and numbats of Africa and Australia, are wholly reliant on ants and termites as their primary food source.
These animals possess features like powerful claws for breaching ant nests, elongated snouts, and sticky tongues, which are poorly suited for catching other prey. For example, a single Giant Anteater must consume up to 35,000 ants per day to meet its energy needs. The disappearance of this food resource would eliminate the foundation of their diet. Specialized ant-eating reptiles, such as horned lizards, and certain birds would also face immediate population pressure, leading to rapid declines and localized extinctions.