Pet dogs may understand a human's point of view, according to new research which suggests they are more likely to steal food when they think nobody can see them.
Dr Juliane Kaminski, of the University of Portsmouth's department of psychology, found that when a human forbids a dog from taking food, dogs are four times more likely to disobey in a dark room than a lit room, suggesting they take into account what the human can or cannot see.
Dr Kaminski said: "That's incredible because it implies dogs understand the human can't see them, meaning they might understand the human perspective."
She said that although many dog owners think that their pets are clever and understand humans, this had not yet previously been tested by science.
The research, published in the journal 'Animal Cognition' and funded by the Max Planck Society, involved a series of experiments in varied light conditions.
In each test, a dog was forbidden by a human from taking the food. When the room was dark, the dogs took more food and took it more quickly than when the room was lit.
In total, 42 female and 42 male domestic dogs aged one year or older took part in the tests.
Dr Kaminski explained that previous studies have shown chimpanzees have a sophisticated understanding and seem to know when someone else can or cannot see them and can also remember what others have seen in the past.
She added that more research was needed to understand what was influencing the behaviour of dogs because their understanding was limited to the "here and now".