The predatory behavior of ants: an impressive panoply of morphological adaptations

Ants are typically omnivorous insects with ovoid heads equipped with short mandibles, but there is great diversity in both the adaptations of their morphological and behavioral traits, as well as their dietary habits. Here, we review the variety of form and function in ant predation. Predation and scavenging were likely the plesiomorphic modes, with Cretaceous ants evolving mandibles well-suited to prey capture. In contemporary ground-dwelling species, mandible morphology can vary with adaptations to capturing particular prey as they may possess trap-jaw, snapping, or falciform mandibles characterized by their high closure speed. To capture termites or other ants, specialized ants may eliminate guards to prey on workers and brood or use allomones that cause the workers of raided nests to flee, providing access to the brood. Among arboreal ants, many species rely on vision to detect flying insects that land on their host trees. In tropical rainforests, territorially dominant arboreal ants (TDAAs) often hunt in groups, spreadeagling their prey, while venom use is noted in only a few species. Some obligate plant-ant species have developed ambush strategies for prey capture, building traps or hiding in shelters. Consequently, ants, due to their large number, their species diversity, and their capacity to live from the ground to tree crowns, regulate all kinds of arthropods through their predation. Ground-dwelling ants impact arthropods in the leaf-litter or provide biotic protection on small plants, but rarely on trees, while the TDAAs that occupy tree crowns protect their host trees from defoliating insects.