Sick young ants, known as pupae, release a specific chemical smell when terminally ill, signaling worker ants to destroy them and protect the colony from disease, scientists revealed in a recent study published in Nature Communications.
This altruistic act helps prevent the spread of infection, as ant colonies function like tightly integrated “superorganisms” focused on collective survival.
How the Signal Works
Researchers found that infected pupae emit a unique chemical profile only when worker ants are nearby, proving it is a deliberate signal for destruction. When the smell was applied to healthy brood in lab experiments, workers still destroyed them, confirming the chemical’s potency. This mechanism is similar to how infected cells in human bodies send out distress signals to be removed.
Why Only Worker Pupae Sacrifice
Queen pupae, however, do not send out this warning signal when infected. Scientists discovered queen pupae have much stronger immune systems, enabling them to fight off infections without needing colony intervention. This is not considered cheating, but rather a reflection of their superior immunity and higher value to the colony.
Evolutionary Benefits and Future Research
By signaling their condition, fatally infected pupae ensure colony health and indirectly pass on their genes through healthy offspring. This finely tuned system balances individual and social immunity, allowing colonies to respond rapidly to threats. Researchers hope to investigate whether queen pupae would sacrifice themselves if their infection became unstoppable.
FAQ: Ant Disease Signaling
Do all ants signal for sacrifice when sick? Only worker pupae do; queen pupae rely on stronger immunity.
How do ants detect the signal? Workers respond to specific chemical changes produced by sick pupae.
Why is this behavior important? It prevents disease outbreaks in crowded colonies.
Can this system be found in other insects? Similar altruistic disease signaling is seen in termites and some other social insects