Ants learn faster after caffeine

Ants that were given a sucrose solution with added caffeine were able to locate the reward locations faster than ants that received a solution without caffeine. However, this does not mean that the ants moved faster, rather the insects found shortcuts and more direct paths to reward, suggesting that caffeine improves their ability to learn.

The caffeine in coffee increases alertness and gives people energy. It helps most of us shake off the last vestiges of sleep and start the day. It is one of the most popular steroids. Caffeine also affects animals. They also experience changes in behavior and physiology under the influence of this compound.

Research conducted by scientists from the University of Regensburg has shown that caffeine can significantly increase the efficiency of ants in searching for food. In experiments, Argentine ants (Linepithema humile), the equivalent of the small black tree, found shorter paths to food sources. According to scientists, experimental results indicate that caffeine supports the learning process. The results and description of the research were published in the journal “iScience”.

Argentine ants are an invasive species. They are also very aggressive – they eliminate other ant species in the colonized area, including species important for the entire ecosystem, and spread plant seeds. They can also threaten native invertebrates and even small vertebrates that are not accustomed to defending themselves against aggressive ants. These ants originated in North America, but can now be found all over the world. Their aggressive behavior and the losses they cause have led to Argentine ants being included in the list of the most aggressive species in the world.

The rest of the article is below the video

Efforts to control Argentine ants have not been entirely successful. They focus on baiting with poison, but this does not produce the desired results. The researchers wanted to know whether using caffeine, which previous studies have shown improves learning ability in bees and bumblebees, could improve the ants’ ability to locate bait and direct their mates there.

– The idea of ​​this project was to find a way to persuade ants to eat more of the poisonous baits that we put in the field, says Henrique Galante from the University of Regensburg. – We found that moderate doses of caffeine actually helped their learning process. If you give them a little caffeine, it gets them on a straight path and they get to the reward faster. He adds that the faster they reach the bait and the more pheromone traces they leave behind, the more ants will follow them and, therefore, the faster they can spread the poison to the entire colony.

To test their hypothesis, the researchers conducted experiments involving ants, a LEGO movable bridge, a sucrose solution, and different concentrations of caffeine. They prepared a path for the ants, ending in a drawbridge, leading to a test platform – a sheet of paper on which the researchers placed drops of a sucrose solution without caffeine with the addition of 25 ppm, 250 ppm or 2,000 ppm caffeine. .

– The lowest dose used is that found in plants, and the average dose is equivalent to the concentration found in some energy drinks – explains Galanti and adds that a similar concentration of caffeine was used as in the higher dose in studies on bees, but half as much. Some of them died.

To track the ants, the researchers used an automated system that monitored how quickly the ants moved to and from the reward and the paths they chose. In total, the researchers tested 142 ants. Each of them took the test route four times. During the experiments, the scientists changed the route slightly so that the ants could not follow their pheromone trail to the place where the caffeine and sucrose solution was located. Feeding time was also measured.

“We performed a series of measurements on the routes they chose and how quickly they found a food source to assess whether caffeine actually improved their learning ability,” Gallant says. The experiments showed that ants that did not receive caffeine followed the same route to the food source, suggesting that they failed to store its location in memory. But ants given low to moderate doses of caffeine (25 and 250 ppm) were more effective at identifying the source.

Foraging time was shortened by 28%. per visit for the ant that received 25 ppm of caffeine, a 38 percent reduction for each visit for the ant that received 250 ppm of caffeine, meaning that if it took the ant 300 seconds to reach the reward on its first visit, it only needed 113 seconds for the low dose of caffeine and 54 seconds for the medium dose on the last visit. Visit. This effect was not observed when taking the highest dose of caffeine.

Scientists have proven that caffeine shortens the time of ants searching for food, which increases their efficiency, but not the speed of their movement. A dose of caffeine had no effect on the ants’ pace, but ants that received low or medium doses of caffeine traveled along less complicated paths. -We noticed that they were not moving faster, but were more focused on where they were going. This indicates they know where they want to go, Gallant says.

Scientists are optimistic. They believe caffeine added to baits could help control Argentine ant populations, but more research is needed first. Researchers are currently testing caffeine-containing baits under natural field conditions in Spain. They also plan to conduct research to see if there is any interaction between caffeine and the bait toxin.

Źródło: Press Cell, New World