Comparison of foraging tool use in two species of myrmicine ants (Hymenoptera: Formicidae)

Abstract

Many ant species are known to exhibit foraging tool use, during which ants place various debris items (e.g., pieces of soil, leaves, pine needles, etc.) into liquid food, and then they carry the food-soaked tools back to the nest. In the present study, we compared the tool-using behavior in captive colonies of two closely related myrmicine ants with different feeding preferences: Aphaenogaster subterranea, an omnivorous species, and Messor structor, a mainly granivorous seed-harvester species. We supplied foraging ants with honey-water baits and six types of objects they could use as tools: sand grains, small soil grains, large soil grains, pine needles, leaves, and sponges. We found that the workers of A. subterranea both dropped more tools into honey-water baits and retrieved more of these tools than the workers of M. structor. While A. subterranea preferred smaller tools over larger ones, tool preferences for M. structor did not differ significantly from random. In addition, tool dropping was significantly faster in A. subterranea, and both the dropping and retrieving of tools began significantly earlier than in M. structor. For Aphaenogaster species that regularly utilize and compete for liquid food sources, the ability to efficiently transport liquid food via tools may be more important than it is for seed-harvester ants. Dropping tools into liquids, however, may still be useful for seed-harvester species as a means to supplement diet with liquid food during periods of seed shortage and also to serve as a means of getting rid of unwanted liquids close to the nest.

Paving Behavior in Ants and Its Potential Application in Monitoring Two Urban Pest Ants, Solenopsis invicta and Tapinoma melanocephalum

“…A well-known tool-use behavior in ants is throwing particles into the liquid food or building siphon tubes to cope with water tension and facilitate liquid feeding [ 24 , 25 , 26 ]. Ants also use particles to absorb liquid food and transport soaked particles back to the nest [ 27 , 28 , 29 ]. However, these behaviors were only observed in the ant subfamily myrmicinae.…”

Unrecognized for centuries: distribution and sexual caste descriptions of the West European Aphaenogaster species of the subterranea group (Hymenoptera, Formicidae)

“… subterranea workers are known to use tools: they drop small debris into liquid food and transport food-soaked tools back into their nest ( Lőrinczi et al 2018 ; Módra et al 2022 ). This behavior is deemed to be a complex strategy developed to compensate for the inability to ingest and carry into the body large quantities of liquid food ( Lőrinczi et al 2018 ; Módra et al 2022 ). Notably, we found multiple times numerous dealate queens (up to five) in some colonies of A.…”

Tool use by foraging ants

“…In this issue, Gábor Módra and colleagues continue their studies of foraging tool use by ants, with a comparison of two species with different foraging habits (Módra et al 2021). They test the hypothesis that tool use should be more frequently observed in ants in which soft or liquid food, such as honeydew, rotten fruit or liquefying corpses of arthropods, represents a significant portion of their diet.…”