Ants Self-Medicate On Toxins To Fight Fungal Diseases

It is noticed that a healthy ant usually keeps away from large quantities of hydrogen peroxide, as it would lead to negative effects physiologically. Yet scientists from the University of Helsinki noticed that ants tend to consume it if they get infected with harmful fungal diseases, which can reduce mortality rates among sick ants, according to discovery.

"The fact that ingestion of this substance carries a fitness cost in the absence of pathogens rules out compensatory diet choice as the mechanism, and provides evidence that social insects medicate themselves against fungal infection, using a substance that carries a fitness cost to uninfected individuals," researchers write.

The team decided to poison healthy ants with harmful hydrogen peroxide in order to prove the theory, and reveal that a healthy ant would always avoid consuming it due to its toxicity. Any consumption in the wild after infection is just due to self-medication, according to wired.

One study lead by the lead author, Nick Bos, said that ants in the wild tend to source hydrogen peroxide from "the decaying bodies of aphids and possibly other ants".

In an experiment, Bos explains to inverse : "Our study adds to the knowledge of self-medication in that it is not just a black and white response. The ants get sick, but they still manage to choose their food according to their needs. They don't just eat all the medicine they can get, but dose it according to its concentration.

"The word self-medication is often used, but the amount of times it has been fully shown are rare. Even though examples of potential self-medication in mammals are plenty, showing that it is actual self-medication and not compensatory diet-choice is very hard. Self-medication requires that the medicine is harmful to healthy individuals (while compensatory diet choice implies the medicine is not harmful), and force-feeding a medicine to primates to show this cost is very unethical. This is where research on insects is very useful. Doing a large-scale experiment like we did is simply not possible with vertebrates."

However, it is not clear how the ants get aware of their infection.

Bos' study "Ants medicate to fight disease" is published in the latest edition of the journal Ecology.