Ants Change Behavioral Patterns to Minimize the Effect of the SIR Epidemic Model
A study from the Institute of Science and Technology Austria reveals that ants change their routines and behavioral patterns to protect the queen and other workers from becoming ill. The societal structure of ants is organized based on age and their roles in the colony. The younger ants are nurses to the broods in the middle of the farm while older ants are foragers who collect food. Naturally, the foragers are more exposed to diseases and pathogens. Because close quarters and frequent contact with others contribute to the rapid spread of diseases, when ants detect disease, they interact more with their own subgroups and less with others. To conduct this experiment, they first barcoded a colony of ants and traced each individual’s movement and social interactions. They then exposed all the foragers, which was 10% of the worker ants, to fungal spores that spread through contact. The ants quickly detected this pathogen and reacted by changing their interactions with each other. Foragers worked more closely with other foragers while nurses stuck with other nurses.
From this experiment, they discovered that even the ants that were not infected changed their behaviors to improve the defense mechanism. They were able to trace the concentration of the fungi on all the ants, and only a few were exposed to a high dose. However, many ants had a small dosage for immune memory, similar to a vaccine. This experiment also highlighted the fact that they protect the most valuable members. The queen, nurses, and younger ants were exposed to the pathogens the least. They also conducted a survival experiment to see if a stronger dose of the fungi correlated to death. Their hypothesis was correct; foragers were more likely to die than nurses, and all queens were still alive. This experiment proved that ant colonies try to minimize the number of interactions that an infected ant has with susceptible ants, therefore reducing the epidemic model. The ants then operate in this modified behavior until the infected become removed. Through carefully studying ants’ behaviors, it can be used as a general model for preventing the spread of infectious diseases.
Link to article: https://www.sciencedaily.com/releases/2018/11/181123135020.htm