Cats Control Mice With Chemicals Found in Their Urine

According to a new study, it has been revealed that mice exposed to cat urine are less likely to escape from their predators.

Scientists learned that when young mice get exposed to a chemical in cat urine during a critical phase of their development, they become less likely to avoid the scents of cats in later life.

Dr. Vera Voznessenskaya, one of the researchers from the AN Severtov Institute of Ecology and Evolution in Moscow said, "Because the young mice (less than 2 weeks-old) are being fed milk while being exposed to the odor, they experience positive reinforcement. So they don't escape the cats when exposed to cat odor later on."

Researchers identified the element found in cat urine as L-Felinine.

When the chemical detecting neurons in mice detect this scent, it usually causes a rise in stress hormone levels.

"It's something that has existed in cats and mice for thousands of years."

"We already knew that odor affects reproduction in mice: in fact, this molecule (L-Felinine) is capable of blocking pregnancy in females and reducing the size of the litter," said Voznessenskaya.

"Early exposure to cat odor changes behavioral reactions to, but not physiological (hormonal) responses in the mice, which remain elevated. In fact, mice that had experienced the odor showed stress response (elevated corticosterone) to cat odors the same way as controls."

Voznessenskaya concludes that mice raised around the scent of cat urine are less likely to show signs of fear or the intention to flee once they smell the scent.

"Habituating like this is probably useful for the mice; they can't run away, because they need to live around humans and food. And cats also live around humans. (Cats) seem to be able to keep the number of mice around that they need."