Unlike humans, when animals come face to face with an infection, they don't have vaccines to cure or prevent the illness. In a phenomenon called behavioral immunity, social animals change their behavior, exemplified by physical distancing for the survival of the entire species.
The Caribbean spiny lobster is one creature observed to respond to diseases by becoming socially distant. When a spiny lobster is infected with a contagion called Panulirus argus virus 1, its urine contains particular chemicals. The off smell signals healthy lobsters to stay away from the harmful virus.
Similar to many other species such as fish, insects, birds, and monkeys, animals can detect those that are sick and those who intentionally distance themselves. This is a part of their survival skills since predators would prey on the weak and the sick.
Animals that know to keep their distance when a sickness breaks out in their group have higher chances of survival. They are also likely to increase their chances of remaining fertile if they stay away from those infected.
Scientists also observed the behavior of healthy lobsters when encountering an infected one. Healthy lobsters are willing to risk their life to predators in open water to search for a new safe haven if a lobster in their previous den is infected with a virus. Groups of lobsters will also shun lobsters that are ill, finding them alone in dens.
Self-Isolating Ants
In an experiment with an ant colony, Natalie Stroeymeyt from the University of Bristol observed the behavior of a colony with a fungus outbreak. Spores of the lethal Metarhizium brunneum spreads within a colony through physical contact, which then causes ants to become ill or die within one or two days. Within 24 hours, the social behavior of infected forager ants significantly changed. Those exposed to the fungus stayed physically distant from the colony.
The healthy forager ants which interacted with the infected ants kept their distance from the colony as well by becoming self-isolated. This behavior was for the survival of the colony.
Furthermore, the 'nurse' ants moved the brood further into the nest away from the infectious fungus. As a result, the queen, nurse ants, and the young ants were kept safe from infection.
READ: Senior Scientists Question WHO-commissioned Study on Social Distance Guidelines
Social Connections
With mandrills, who are social primates and can be found in groups of hundreds in the African rainforests, what changed in their behavior would be the grooming practices. Grooming is a natural part of their daily activities, which change if there is one sick mandrill among them.
An infected mandrill is detected by the smell of his or her feces, which cue the other mandrills to stay away. However, this was not always the case. Sometimes, they would continue to groom close relatives with parasites.
This is probably due to the importance of social ties in their species. Highly social females in a group of mandrills typically breed earlier and produce more offspring. Therefore, they are willing to risk grooming infected relatives for the sake of connections.
Putting together all of these behaviors are very similar to humans react to infection, especially with the deadly coronavirus being easily transmissible. Social connections are essential to human survival, but can also be controlled and altered to keep each other safe from infection.
