Key takeaways
- Ants may forage for food individually or recruit other members of their colonies to help them find or carry food to their nests.
- UCLA biologists found that the strategies ants use to forage play a bigger role in how they build their nests than do innate, evolutionary „blueprints.”
- When building nests, ants strike a balance between transport efficiency and architectural barriers. Researchers say tracking could help humans design more efficient transportation systems tailored to specific needs.
Could Ant Nests Hold the Secret to Reducing Traffic on the 405 Freeway?
In a new study, UCLA biologists have discovered insights into how ants build their nests that could be useful for designing more efficient human transportation systems.
Scientists were interested in learning whether the way ants build their nests is more influenced by the evolutionary history of each individual species or by current environmental conditions. What they found was that evolution could not explain the variations they observed in the nests of different species. Instead, they found, the environment in which the ants forage and the way they carry food are key factors that dictate how each species builds its nests.
A lesson for humans? If roads are better designed to accommodate the movement of goods and people through our cities, transport networks will be more efficient. For example, congestion on Southern California’s freeways could improve if trucks had dedicated lanes or roads going to major logistics centers such as ports, warehouses, and distribution centers.
„Ants deal with the same problems we face when living in crowded spaces,” said Sean O’Fallon, a UCLA doctoral student in ecology and evolutionary biology and first author of the study. „We’re densely packed into cities, and we need to be densely connected, but there are limits to how close together we can be. There’s only so much space for buildings and roads.
In the study, Published in the Philosophical Transactions of the Royal Society B, the scientists analyzed information from two sources – details about 397 ant nests came from previously published data and images, and the authors made new studies of 42 other nests, all at the Arkbold Biological Reserve near Venus. , Florida. In total, 439 nests represented 31 different species of ants.
They discovered that nest structures are largely determined by factors such as whether ants forage singly or in groups, and the methods by which they recruit other ants to find and carry food. In short, animal activity and behavior play larger roles in nest construction than any inherent evolutionary template.
„You can think of the nest as a transportation network—it’s where the ants live, but it’s also a kind of highway network that moves things in and out,” said Noah Pinter-Volman, professor of ecology and evolutionary biology at UCLA. Corresponding author of the paper.
The researchers examined four common feeding strategies used by ants. In some species, individual ants hunt for food. In others, an ant brings food to nests as a means of providing other ants with a food source. Ants can create a continuous path between the food source and the nest that can last for months. Or they could leave a pheromone trail that could be followed in large numbers by members of the colony — what the researchers called „mass recruitment.”
Ant nests have a tunnel leading to an entrance chamber where ants help other members of their colony find or transport food. From the entrance chamber, tunnels lead to other chambers, which are connected by tunnels to even deeper chambers. Chambers serve a variety of purposes, such as storing food and waste and raising young.
The researchers expected that in ant species that use a recruitment system, the entrance chambers of the nests would be larger than in the nests of other species, because those spaces should allow contact with large numbers of ants. Indeed, they found it to be so.
However, the scientists expected mass recruitment nests to have a higher „network density” than nests built by other species. Scientists hypothesize that higher network density may help facilitate greater movement of ants and resources throughout the nest.
But for ants representing all four feeding strategies, network density was relatively low—even for large nests with hundreds of chambers. Indeed, the study revealed that among all feeding strategies, nests with more chambers had lower network density.
In the paper, the researchers write that the finding may simply be a function of the architecture: Multiple tunnels between chambers could weaken the nest’s structural integrity, causing the entire structure to collapse.
„Ants must balance the efficiency of highly connected nests with architectural stability,” Pinter-Wolman said. „On the one hand, they want traffic to be faster, but if they start building more links, the nest will crumble.