Does your dog have a jealous streak?
A new study says canines can feel jealousy.
Researchers at the University of California San Diego had owners plan with an animatronic toy dog, children's book, and a plastic jack-o'-lantern while ignoring their pets.
It turns out, most of the dogs didn't like it one bit.
Some of them got aggressive, pushing their owners while they played with the fake dog.
And most tried to sniff the bottom of the boy dog, suggesting they thought it was real.
Researchers think jealousy may have evolved in dogs, because they've been domesticated for so long.