Antlion larvae are fascinating insects best known for constructing conical pits in dry, sandy soil to trap unsuspecting prey, primarily ants. The term “antlion” refers specifically to the larval stage, which is a voracious predator. The adult stage, however, is a delicate, winged insect resembling a damselfly or lacewing, and is not generally considered a pest. While the larvae are not destructive to human property or health, their presence is notable in yards, gardens, and playgrounds that feature exposed, sandy soil.
Taxonomy and Classification
Antlions belong to the family Myrmeleontidae in the order Neuroptera (net-winged insects), which also includes lacewings and mantispids. The genus name *Myrmeleon* literally means “ant-lion.” They undergo complete metamorphosis (egg, larva, pupa, adult). The antlion larva is the only predatory stage, while the adult is generally short-lived and feeds on pollen and nectar, or does not feed at all.
Physical Description
The antlion larva is squat, camouflaged, and grub-like, typically 5–15 millimeters in length. It has a robust, segmented body covered in bristly hairs. Its most distinctive feature is its massive, sickle-shaped jaws (mandibles), which are hollow and used to inject venom and digestive enzymes into prey. The larva is often hidden at the base of its pit, with only the mandibles visible.
The adult antlion is a poor flyer, resembling a damselfly but generally stockier and possessing long, clubbed antennae. Its wings are delicate, clear, and veined, and it is usually nocturnal or crepuscular (active at dawn/dusk), often resting during the day in vegetation.
Distribution and Habitat
Antlions are found globally, particularly in arid and semi-arid regions. The larvae require dry, loose, fine-grained soil or sand to construct their signature traps. They are commonly found under overhanging structures that protect the sand from rain, such as beneath eaves of houses, rock ledges, bridges, or in the protected corners of foundations and garages. Their habitat is restricted by the need for stable, dry terrain where the conical pit can be maintained.
Behavior and Life Cycle
The female adult deposits eggs in dry, sandy soil. The resulting larva immediately begins digging its characteristic pit. It does this by moving backward in a spiral motion, flicking sand away with its head and mandibles, until a conical depression is formed. The larva then buries itself at the base of the cone, waiting for prey to fall in.
The larval stage can last from one to several years, depending on food availability. When ready to pupate, the larva spins a spherical silken cocoon, which is covered in sand grains, and remains buried until the adult emerges. Adults live for only a few weeks, focusing on reproduction.
Feeding and Trapping
The antlion larva is a passive, sit-and-wait predator. Ants or small insects that wander near the edge of the pit fall onto the steep, unstable slope. As the prey slides down, the antlion, hidden at the bottom, may rapidly flick sand at the victim, causing miniature “landslides” that hasten the prey’s descent. Once the prey reaches the bottom, the antlion grabs it with its powerful mandibles, injects venom and enzymes, and then sucks out the liquefied contents. The carcass is then flicked out of the pit, and the trap is repaired for the next victim.
Interaction with Humans and Animals
Antlion larvae are ecologically beneficial, as they prey on ants and other small, ground-dwelling insects. They do not sting, bite, or carry disease, and are harmless to humans and pets. Their pits are sometimes considered a minor nuisance in sandboxes or yards, but they are generally viewed as a curiosity rather than a pest requiring control. The presence of a high number of antlions is often an indicator of a large ant population that serves as their food source.
Management and Prevention
No management or control of antlion larvae is typically recommended or necessary, as they are non-destructive and help control ant populations. If pits are undesirable in a specific location (e.g., a high-traffic area), simply disturbing the sand or covering it with a finer mulch or gravel will disrupt the pit construction and force the larvae to relocate. Applying water to the area also makes the soil unsuitable for pit building.
Conservation and Research
Antlion larvae are not endangered and are ecologically important as specialized predators. Research on antlions focuses primarily on their biomechanics—how they construct their elaborate, geometrically perfect traps, and how they use sand-flinging as a means of prey capture. They are often studied as a model for complex, passive predation strategies in the insect world.