Researchers have observed ants secreting a milk-like fluid that feeds others in the colony.

According to the research, published in Nature on 30 November, ants produce a fluid that is eaten by both adults and larvae.

This fluid is similar to how newborn mammals depend on milk. If the ant adults don't consume the fluid, it will build up and become contaminated with fungi, which will kill the pups.

According to co-author Orli Snir, a biologists at the Rockefeller University in New York City, there is a mechanism that bonds the colony.

Patrizia d'Ettorre is an ethologist at Sorbonne Paris North University. The pupae were considered useless because they were immobile, didn't eat, and were just moved around by the workers. This paper proves that this isn't true.

The discovery was made by observing a colony of raider ants at different stages of their life cycle.

The researchers were surprised to see droplets of a fluid on their abdominal tips. The pupae survived even though they drowned in the fluid.

By injecting blue food dye into the pupae and tracing where it ended up, the researchers showed that adult ants drink the fluid and help their offspring drink it. The fluid can't accumulate. The adults are taking the pupae and putting them on the pupae to feed.

The team was able to identify more than 100 different compounds in the fluid, as well as 185 genes that were specific to it. The compounds suggest that the fluid is derived from moulting fluids, which are produced when the larvae shed their outer cuticle. Adria LeBoeuf is a Biologist at the University of Fribourg.

Evolutionary role

The researchers think that pupal milk could play a part in the evolution of ant social structures. The co-author of the book says that it has evolved after ants became social.

The team wants to study the effects that pupal secretions have on the adults and their offspring. The amount of access they have to this fluid may affect whether a queen or worker is formed.

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Karsten Schnrogge, an ecologist at the UK Centre for Ecology & Hydrology in Wallingford, would like to see research on whether the pupae is useful in the transfer of gut flora that helps ants digest food.

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