AFP, Paris

Sick young ants release a smell to tell worker ants to destroy them to protect the colony from infection, scientists said Tuesday, adding that queens do not seem to commit this act of self-sacrifice.

Many animals conceal illness for social reasons. For example, sick humans are known to risk infecting others so they can still go to the office -- or the pub.

Ant colonies, however, act as one “super-organism” which works to ensure the survival of all, similar to how infected cells in our bodies send out a “find-me and eat-me” signal, according to an Austria-led team of scientists.

Ant nests are a “perfect place for a disease outbreak to occur because there are thousands of ants crawling over each other,” Erika Dawson, a behavioural ecologist at the Institute of Science and Technology Austria and lead author of a new study, told AFP.

When adult worker ants get an illness that could spread through the colony, they leave the nest to die alone. Young ants, known as pupae, in contrast are still trapped inside a cocoon.

Scientists had already figured out that when these pupae are terminally ill, there is a chemical change that produces a particular smell.