Mice can tell when others are stressed through their sense of smell and may feel a similar pain, according to new research published in Science Advances.

Researchers discovered that mice transfer pain sensitivity to their neighbors through odor after they exposed a group of mice — some of which were experiencing withdrawal and some of which were given a chemical to cause irritation — to certain experiences that cause pain, such as dipping their tails in warm water. A second group of mice nearby, which hadn’t been going through withdrawal and were not given the chemical irritant, picked up on the pain sensitivity of the first group.

In the experiment, scientists brought straw lining from the first mouse group to an isolated control group in another room and discovered that those mice, despite having no contact with the others, picked up on the pain via scent.

“Olfactory cues mediate the transfer … to the bystander mice, which can be measured using mechanical, thermal, and chemical tests,” the study says.

The team, from the Oregon Health and Science University, was inspired to investigate the link between scent and pain after noticing, in another experiment involving alcohol and cocaine withdrawal in mice, that other non-addicted mice became sensitive to the same pain as the afflicted mice.

"Bystander mice housed and tested in the same room as mice subjected to inflammatory pain or withdrawal from morphine or alcohol develop corresponding hyperalgesia,” which is a heightened sensitivity to pain, the study notes. “These experiments reveal the multifaceted relationship between the social environment and pain behavior and support the use of mice as a model system for investigating these factors.”

It also says the study shows a need for researchers to properly consider how to house and test animals in a laboratory experiment.

Mice are not the only creatures who experience sympathetic pain. Some men whose wives are having babies experience couvade syndrome, also known as sympathetic pregnancy. The Mayo Clinic notes the symptoms can be both physical and psychological, bringing nausea, heartburn, abdominal pain, backaches, anxiety and restlessness, among others.

Source: Smith ML, Hostetler CM, Heinricher MM and Ryabinin AE. Social transfer of pain in mice. Science Advances. 2016.