Ants consume moths, but the nature of this interaction varies significantly depending on the circumstances. As generalist foragers, ants incorporate a wide range of organic matter into their diet, including other insects. This makes Lepidoptera—the order encompassing moths and butterflies—a potential food source. The consumption of moths ranges from active hunting to opportunistic feeding, influenced by the ant species, the moth’s developmental stage, and the prey’s health.
The Primary Interaction: Predation or Scavenging?
Ants acquire moths through either predation or scavenging, though most ant species operate as generalist “scavenging predators.” Scavenging is the most common route for ants to consume adult moths, involving animals that are already dead, injured, or otherwise incapacitated. A moth that has died naturally or is grounded due to injury presents a stationary, high-calorie food item that can be transported back to the colony.
Active predation, where ants kill a live, healthy moth, requires a significant investment of effort and is less frequent for flying adults. This active hunting often involves a coordinated, overwhelming attack by multiple workers to subdue a large insect. A single foraging ant is rarely a match for a healthy adult moth, which uses flight as an immediate escape mechanism.
Moth Life Stages as Prey
A moth’s vulnerability to ant attack changes dramatically throughout its four life stages. Caterpillars, the larval stage, are the most susceptible targets for ant predation due to their soft bodies and lack of mobility. Early-instar larvae, which are small and lack developed defenses, are easily captured and carried away by a single foraging ant.
The pupal stage, where the moth is enclosed in a cocoon or chrysalis, is also highly vulnerable as it is completely immobile. While often protected within soil or hidden structures, exposed pupae become easy targets for ground-foraging ants. Adult moths possess the distinct advantage of flight and a covering of scales that can make them difficult to grip, serving as physical defenses that deter smaller predators.
Specialized Ant Predators
Certain ant groups possess the specialized morphology and behavior necessary to regularly prey on large insects like adult moths or late-instar caterpillars. Aggressive species, such as some members of the Ponerine ants or Army Ants, are known for their highly predatory habits and coordinated hunting strategies. Army ants, for instance, form massive foraging columns that overwhelm virtually all ground-dwelling arthropods in their path, including any moth larvae or exposed pupae.
Other aggressive ants, like the arboreal species Pseudomyrmex gracilis or some Camponotus species, are known to actively attack caterpillars feeding on host plants. These hunters possess morphological adaptations, such as specialized mandibles or potent venom, that allow them to subdue prey larger than themselves. In contrast, smaller, less specialized ants, such as common pavement ants (Tetramorium), are typically restricted to scavenging or consuming only the smallest, most defenseless moth larvae.