Ants take medicine to get well, a new study by Finnish researchers has found. But they don't have doctors - they self-medicate.
There have been various theories and observations on medicinal use by insects, like bumble bees, but nothing was confirmed. This is the first time experimental confirmation of self-medication has been done.
The black ant Formica fusca is found in Finland. Research scientists from University of Helsinki, Finland, did a series of experiments and found that when the ants got infected by a local fungus, they would seek out and eat certain type of food.
"It is an amazing discovery that ants have an idea of their health status and seem to adjust the dosage of medicine correspondingly," said researcher Nick Bos.
The scientists confirmed that the sick ants were eating hydrogen peroxide to fight the fungus - and the strategy was working. Hydrogen peroxide is an antiseptic and is also used for bleaching. It releases free oxygen that kills off fungus. Ants find it in damaged plants, other insects and cadavers.
"When ants are feeding on the diet containing extra free radicals they are able to survive infections significantly better. Moreover, the ants also choose the diet including extra free radicals after they are exposed to fungus, but not in its absence," says researcher Dalial Freitak from the Faculty of Biological and Environmental Sciences.
Hydrogen peroxide containing food was avoided by healthy ants and eaten only by infected ones, the researchers found. If healthy ants are given hydrogen peroxide it damages their health. So it was definitely a choice being made by the ants.
Also, when the scientists increased the quantity of hydrogen peroxide available for consumption, the ants consumed less of it. This implied that the ants were consuming a certain dosage of the 'medicine'.
The scientists found that taking the medicine increased the chances of infected ants surviving by 20 percent. The fungal disease is lethal to these ants.