{"id":27786,"date":"2025-01-08T11:50:37","date_gmt":"2025-01-08T10:50:37","guid":{"rendered":"https:\/\/uni-freiburg.de\/en\/?p=27786"},"modified":"2025-01-08T12:35:27","modified_gmt":"2025-01-08T11:35:27","slug":"evolutionary-biology-ants-can-hold-a-grudge","status":"publish","type":"post","link":"https:\/\/uni-freiburg.de\/en\/evolutionary-biology-ants-can-hold-a-grudge\/","title":{"rendered":"Evolutionary biology: Ants can hold a grudge"},"content":{"rendered":"\n
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Freiburg, 08\/01\/2025<\/em><\/p>\n\n\n\n

A team led by evolutionary biologist Volker Nehring is investigating the extent to which ants learn from past experiences.<\/strong><\/strong><\/p>\n<\/div>\n\n\n\n

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Ants behave more aggressively towards conspecifics from a particular nest if they have previously been attacked by others from that nest. Photo: Dr Volker Nehring<\/em><\/figcaption><\/figure>\n<\/div>\n\n\n\n
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Ants learn from experience. This has been demonstrated by a team of evolutionary biologists from the University of Freiburg, led by Dr Volker Nehring<\/strong>, research associate in the Evolutionary Biology and Animal Ecology group, and doctoral student M\u00e9lanie Bey<\/strong>. The researchers repeatedly confronted ants with competitors from another nest. The test ants remembered the negative experiences they had during these encounters: when they encountered ants from a nest they had previously experienced as aggressive, they behaved more aggressively towards them than towards ants from nests unknown to them. Ants that encountered members of a nest from which they had previously only encountered passive ants were less aggressive. The biologists published their results in the journal Current Biology<\/em>.<\/p>\n<\/div>\n<\/div>\n\n\n\n

Ants are aggressive towards their neighbours<\/strong><\/strong><\/h2>\n\n\n\n

Ants use odours to distinguish between members of their own nest and those from other nests. Each nest has its own specific scent. Previous studies have already shown that ants behave aggressively towards their nearest neighbours in particular. They are especially likely to open their mandibles and bite, or spray acid and kill their competitors. They are less likely to carry out such aggressive manoeuvres against nests that are further away from their own. Until now, it was unclear why this is the case. Nehring’s team has now discovered that ants remember the smell of attackers. This is why they are more aggressive when confronted with competitors from nests they are familiar with.<\/p>\n\n\n\n

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\n\t\t\t\t\u201cWe often have the idea that insects function like pre-programmed robots. Our study provides new evidence that, on the contrary, ants also learn from their experiences and can hold a grudge.\u201d\t\t\t<\/p>\n\t\t\t\t\t\t\t\t\t

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\n\t\t\t\tDr. Volker Nehring\t\t\t<\/h3>\n\t\t\t\t\t\t

\n\t\t\t\tAcademic Councilor, Department of Evolution and Ecology, University of Freiburg\t\t\t<\/h4>\n\t\t\t\t\t\t\t\t<\/div>\n\t<\/div>\n<\/div>\n\n\t<\/div>\n\n\n\n
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More aggressive behaviour towards competitors from familiar nests<\/strong><\/strong><\/h2>\n\n\n\n

The scientists conducted an experiment in two phases. In the first phase, ants gained various experiences: one group encountered ants from their own nest, the second group encountered aggressive ants from a rival nest A, and the third group encountered aggressive ants from rival nest B. A total of five encounters took place on consecutive days, with each encounter lasting one minute.<\/p>\n\n\n\n

In the subsequent test phase, the researchers examined how the ants from the different groups behaved when they encountered competitors from nest A. The ants that had already been confronted with conspecifics from this nest in the first phase behaved significantly more aggressively than those from the other two groups.<\/p>\n\n\n\n

To test the extent to which the higher aggression arises from the behaviour of ants from a particular nest, the scientists repeated the experiment in a slightly modified form. In the first phase, they now distinguished between encounters with aggressive and passive ants. They ensured that an ant behaved passively by cutting off its antennae. In phase two of the experiment, the ants that had previously only encountered passive competitors behaved significantly less aggressively.<\/p>\n\n\n\n

\u201cWe often have the idea that insects function like pre-programmed robots,\u201d says Nehring. \u201cOur study provides new evidence that, on the contrary, ants also learn from their experiences and can hold a grudge.\u201d Next, Nehring and his team will investigate whether and to what extent ants adapt their olfactory receptors to their experiences, thus reflecting what they have learned at this level as well.<\/p>\n<\/div>\n\n\n\n

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Further Information<\/h3>\n\n\n\n
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