Like humans, ants too change their decision-making strategies based on their real-life experiences, thus, changing their priorities frequently.
Humans and animals need to make various kinds of decisions daily including what to eat, how to protect themselves and where to stay. While the decision-making process in humans has been studied on several occasions, a new study is the first one to look at how animals, ants in specific, make these decisions.
Arizona State University researchers Taka Sasaki and Stephen Pratt have been studying ants for years, adapting psychological theories and experiments that are designed for humans to ants, hoping to understand how the collective decision-making process arises out of individually ignorant ants.
"The interesting thing is we can make decisions and ants can make decisions - but ants do it collectively," said Sasaki. "So how different are we from ant colonies?"
For the study, the team of researchers conducted a series of experiments where colonies of Temnothorax rugatulus ants were made to decide between nests with varying features. For example, in one experiment the entrance size of the nests varied while in another nest exposure to light was manipulated. Since ants are known to prefer nests with smaller entrances and lower light exposure, they have to prioritize their preferences before making a decision.
"It's kind of like a humans and buying a house," said Pratt, an associate professor with the school. "There's so many options to consider - the size, the number of rooms, the neighborhood, the price, if there's a pool. The list goes on and on. And for the ants it's similar, since they live in cavities that can be dark or light, big or small. With all of these things, just like with a human house, it's very unlikely to find a home that has everything you want."
Finding the perfect habitat is very important for ants. Therefore, they need to make various tradeoffs for certain qualities, prioritizing the most important aspects. While choosing between two nests, researchers found that ants displayed a unique sense of intelligence.
Researchers noted that in the experiment where entrance sizes were varied, ants prioritized entrance size over light exposure and vice versa in the experiment where they had to decide between levels of light exposure. This led researchers to conclude that, like people, ants take the past into account when weighing options while making a choice. The difference is that ants somehow manage to do this as a colony without any dissent.
"This helps us learn how collective decision-making works and how it's different from individual decision-making," said Pratt. "And ants aren't the only animals that make collective decisions - humans do, too. So maybe we can gain some general insight."
