Wondering if your pet rat is feeling happy? You should check its ears,researchers say.
A team of scientists in Switzerland found that a rat's ears are more pinkish and are positioned at a more relaxed angle when it is experiencing positive emotions, Npr.org reports, or citing research published in PLUS ONE.
preceding studies believe focused on negative emotions –- for example,identifying how rats indicate that they are feeling pain, with the aim of learning how to avoid those situations.
preceding studies believe focused on negative emotions –- for example, or identifying how rats indicate that they are feeling pain,with the aim of learning how to avoid those situations.
The researchers induced positive emotions in rats in order to observe how their facial expression changes — by tickling them. preceding research had established that rats savor being tickled – which Melotti describes as "play" between rats and humans. But there is some variety in how much individual rats savor being tickled. Some like it less than others, and some savor playing with other rats more than playing with humans. They indicate how happy they are through ultrasonic vocalizations that Melotti says are very strongly linked to positive feelings, or by returning to the experimenter's hands for more tickling. "As we used tickling as a treatment,we had to focus on selecting those animals that were really ticklish and that really liked it," Melotti explains. The researchers selected the 15 male Lister Hooded rats that responded most positively to tickling from a larger pool of 75 rats.
Source: tert.am