Ant nests could help humans build better transportation systems

Ants forage for food either individually or in groups, by recruiting other members of their colonies to help search for and transport food back to their nests. Now, a team of biologists led by the University of California, Los Angeles (UCLA) has found that ants’ foraging strategies play a larger role in how they build their nests than innate, evolutionary “blueprints” do. 

According to the experts, when building their nests, ants reach a balance between architectural constraints and transportation efficiency, a finding which could help humans design more efficient transportation networks tailored to a variety of specific needs.

Focus of the research 

Scientists have long thought that the way ants build their nests is more influenced by the evolutionary history of each individual species than current ecological conditions. 

However, the new study has revealed that the environments in which ants live and the ways they transport food are actually the main factors dictating how each species builds its own specific types of nests. 

Significance of the study

These findings could have major implications for the ways humans could design more efficient transportation systems. 

For instance, congestion on Southern California’s freeways could be improved if there were dedicated lanes or roads for trucks traveling to and from major logistics hubs such as ports, distribution centers, and warehouses.

“Ants deal with the same issues we deal with when it comes to living in crowded spaces,” said lead author Sean O’Fallon, a doctoral student in Ecology and Evolutionary Biology at UCLA. “We’re densely packed in cities, and ideally we should be densely connected, but there are constraints to how closely packed together we can be. There’s only so much space to construct buildings and roads.”

How the research was conducted 

To better understand how ants build their nests, the researchers analyzed data from 439 nests representing 31 different ant species. 

While information about 397 of these nests came from previously published studies, the authors also collected data from 42 additional nests located at the Archbold Biological Reserve near Venus, Florida.

What the researchers learned 

The analyses revealed that nest structures were largely determined by factors such as whether ants foraged alone or in teams, as well as the techniques they used to recruit other ants to help locate and carry food. 

Thus, the ants’ behavior and activity seemed to play bigger roles in nest construction than any innate evolutionary template.

“You can think of the nest itself as a transportation network – it’s where ants live, but it’s also a kind of highway network they move things in and out of,” said senior author Noa Pinter-Wollman, a professor of Ecology and Evolutionary Biology at UCLA.

Common foraging strategies 

The scientists investigated four common foraging strategies employed by ants. While in some species, individual ants forage for food, in others, an ant brings food to the nest as a way of recruiting other ants to accompany it to the food source. 

Ants may also form a continuous trail between the food source and the nest which can persist for months, or they leave pheromone trails that other members of their colony can follow in large numbers (a phenomenon known as “mass recruitment”).

Nest chambers

Ants’ nests consist of a tunnel connected to an entrance chamber, where ants “enlist” other conspecifics to help them find and transport food. 

From this entrance chamber, more tunnels lead down to other chambers, which are connected by yet more tunnels to even deeper chambers. Different chambers have different purposes, such as food and waste storage or rearing offspring.

The scientists discovered that in ant species that use mass recruitment to forage, the nests’ entrance chambers were bigger than they were in other species’ nests, in order to allow a larger number of insects to interact. 

Network density 

However, they also expected that nests for mass recruitment foragers would have greater network density – i.e. larger number of connections between chambers – than other species’ nests, to facilitate more movements of ants and resources throughout the nest.

Surprisingly though, the investigations revealed that, for ants representing all four foraging strategies, network density was relatively low, even in the case of large nests with hundreds of chambers. In fact, nests with the most chambers tended to have the lowest network density.

Study implications 

Although further research is needed to elucidate this phenomenon, the researchers assume that this could simply reflect an architectural constraint, since too many tunnels between chambers can weaken the structural integrity of the nest, causing the entire system to collapse.

“Ants have to balance the efficiency of highly connected nests with architectural stability. On one hand, they want transportation to be faster, but if they start making too many connections, the nest will crumble” Pinter-Wollman concluded.

The study is published in the journal Philosophical Transactions of the Royal Society B: Biological Sciences.

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates.

—–

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.