Infected ant colonies chose food containing hydrogen peroxide, which healthy colonies avoided, and this choice was linked to better survival, according to research reviewed by Gram. A 2026 study in Proceedings B also tied this behavior to a gene called Malvolio, which is active in immune responses and taste.
Animals sometimes change what they eat when they get sick, a behavior called self-medication. A new study, published in 2026 in Proceedings B, tested this in Lasius platythorax, a type of ant where the behavior had not been documented before. Researchers gave ant colonies a choice between normal food and food containing hydrogen peroxide. Colonies infected with a fungal pathogen chose the medicinal food more often, while healthy colonies avoided it. The infected colonies that ate it also showed better survival. The team also found that a gene called Malvolio, which is tied to both immune responses and taste in other insects, became more active after infection. Its daily activity closely followed how often colonies visited the medicinal food. According to research reviewed by Gram, these findings suggest that changes in taste sensing may help drive this healing behavior.
Key Statistics
A 2026 study published in Proceedings B found that ant colonies infected with a fungal pathogen increased their preference for food containing hydrogen peroxide, a choice that healthy colonies avoided.
In the same 2026 study, researchers found that daily activity of the Malvolio gene closely tracked how often infected Lasius platythorax colonies visited the medicinal food during a prolonged infection trial.
The Quick Take
- What they studied: Do sick ants change their food choices to help themselves recover, and what biological changes might drive that behavior?
- Who participated: The participants were colonies of Lasius platythorax, a species of ant. The exact number of colonies was not reported in the study summary. Some colonies were infected with a fungus, and others were healthy.
- Key finding: Infected ant colonies increased their preference for food containing hydrogen peroxide, which healthy colonies avoided. Infected colonies that ate the medicinal food also survived better. Activity of a gene called Malvolio rose after infection and closely matched how often colonies chose the medicinal food.
- What it means for you: This is research on ants, not people, so it cannot tell us what to eat when we are sick. It does offer a clearer look at how infection may change taste and behavior, which could guide future studies on how animals and possibly humans sense and respond to illness.
The Research Details
Researchers gave ant colonies a choice between a standard food and a food containing hydrogen peroxide, a compound with antimicrobial properties. Some colonies were infected with a fungal pathogen, which is a disease-causing fungus, while others stayed healthy. This allowed the team to compare how sick and healthy colonies chose between the two foods.
To understand the biology behind the behavior, the scientists measured gene activity in the ants. Genes are instructions inside cells that control how the body works. By comparing gene activity in infected and healthy ants, the team could spot which genes changed after infection. They then focused on Malvolio, a gene already known to play roles in immune function and taste in other insects.
The researchers also tracked gene activity every day during a long infection trial. This let them check whether changes in Malvolio activity lined up with changes in how often the colonies visited the medicinal food over time.
Combining behavior tests with gene measurements helps show both what the ants did and why they may have done it. Watching the same colonies over many days is especially useful, because it shows whether changes in gene activity happen at the same time as changes in food choices. This timing makes a link between the two more convincing than a single snapshot would be.
The study uses several methods that support each other, including behavior tests, gene analysis, and daily tracking, which strengthens the overall picture. It was published in a peer-reviewed scientific journal, meaning other experts reviewed it before publication. However, the study summary does not state the number of colonies, so it is hard to judge how many ants or groups were tested. The results come from one ant species and one type of infection, so they may not apply to other species or diseases.
What the Results Show
The clearest result was a difference in food choice. Colonies infected with the fungal pathogen increased their preference for the food containing hydrogen peroxide. Healthy colonies avoided that same food. This pattern suggests the infected ants were actively seeking out a substance that may help fight the infection.
The researchers also found that infected colonies that ate the medicinal food survived better than infected colonies that did not. This connection between choosing the medicine and staying alive supports the idea that the behavior is useful to the ants, not just a random change.
The gene analysis showed that infection changed the activity of many genes. Among them, Malvolio stood out because it is linked to immune responses and taste perception in other insects. This gives a possible biological route for how a sick ant might sense and prefer the medicinal food.
The daily tracking added another layer. Changes in Malvolio activity closely followed how often colonies visited the medicinal food across the trial. The study describes this as a strong correlation, which means the two moved together. A correlation alone does not prove that Malvolio causes the behavior, but it supports the idea that it plays an important role.
The study also confirmed that Lasius platythorax engages in self-medication, which had not been reported in this species before. This widens the list of animals known to adjust their diet to fight disease. The results also point to changes in sensory pathways, meaning the ways animals taste and smell, as one possible mechanism behind these choices.
Self-medication has been documented in several animal groups, including insects, birds, and mammals. Earlier work mostly showed that animals choose medicinal foods when sick, but it often did not explain the internal biology behind those choices. This study adds a possible explanation by linking a taste-related gene to the behavior. It fits with a growing view that the immune system and the senses work together to guide behavior during illness.
The study was done in ants, so its findings may not transfer directly to humans or to other animals. The summary does not report how many colonies were tested, which makes it harder to judge how strong the results are. The study also shows a correlation between Malvolio activity and food choice, which does not prove that Malvolio directly causes the change. Further experiments would be needed to confirm its exact role. The study used one fungal infection and one medicinal compound, so results may differ with other diseases or treatments.
The Bottom Line
Based on this single study in ants, the evidence supports the idea that infection can change feeding choices in a way that may help survival. Confidence is moderate for this species, since the findings are consistent across behavior, survival, and gene activity. Confidence is low for any direct application to people, because no human data were collected. Scientists will need more studies before drawing conclusions about human eating habits during illness.
Researchers who study animal behavior, immunity, and taste will find this work especially relevant. Students and science readers interested in how the body and senses respond to disease may also find it useful. People looking for practical advice about food and illness should not apply these findings to their own diets, since the study did not involve humans. Anyone who is sick should continue to follow guidance from a doctor.
This research is at an early stage. Follow-up studies in other species and, eventually, possibly in humans would be needed before any practical applications could emerge. That process typically takes years of testing. For now, the results are best viewed as a step toward understanding how infection shapes behavior.
Frequently Asked Questions
Do sick ants eat medicine on purpose?
Infected Lasius platythorax colonies increased their preference for food containing hydrogen peroxide, while healthy colonies avoided it. Colonies that ate the medicinal food also showed better survival, suggesting the behavior helps them recover from a fungal infection.
What is the Malvolio gene and why does it matter in self-medication?
Malvolio is a gene linked to immune responses and taste perception in other insects. In this 2026 ant study, its daily activity closely tracked how often infected colonies chose the medicinal food, pointing to a possible role in self-medication.
Does this study show that humans should change their diet when sick?
The study was conducted only in ants, so it does not show that people should change their diet during illness. It offers insight into how infection may alter taste and behavior, but human research would be needed before any dietary advice could be made.
What is self-medication in animals?
Self-medication is when animals change what they eat to include compounds that help fight disease or parasites. Many animals are known to do this, and this 2026 study confirmed the behavior in Lasius platythorax ants, a species where it had not been reported before.
Want to Apply This Research?
- If you use the app to log meals, add a simple note each time you are sick about what you eat and how you feel that day, such as a 1 to 5 rating for energy and appetite. This creates a personal record you can review to see patterns over time. Remember this is a personal log, not a test of medicinal foods.
- Use the app to pause and check in with a doctor or pharmacist before changing your diet to treat an illness. The study does not show that eating any specific food helps people. Instead, log your symptoms and meals so you can share an accurate record with a healthcare provider.
- Over the long term, track appetite, fluid intake, and general well-being during any illness, along with a short note on how you feel each day. Review these logs after an illness ends to see patterns that could be useful when talking with a clinician. Keep the focus on symptoms and habits rather than treating any single food as a cure.
This article describes research conducted on ants, not humans. The findings are early and should not be used to make decisions about diet, supplements, or treatment for any illness. Anyone who is sick should talk with a doctor, pharmacist, or other qualified healthcare professional before changing their diet or taking any substance to treat a health condition.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.