Most pet cats form strong bonds with their caretakers and appear to find their presence reassuring. However, unlike human babies, cats don’t accept scent alone as a worthy stand-in for the people they have bonded with, says Kristyn Vitale at Unity College in Maine.

“Olfaction is an important sense for cats, and it’s related to their social behaviour, but in our study, [owner-scented objects] did not have a stress-reducing effect,” she says. “The smell might even make matters worse for some cats.”

— Read more in Cats refuse to snuggle with objects that smell like their owners at NewScientist.