Dogs may understand their owners better than we think, research suggests.

Tests show they are more likely to steal food when they think nobody can see them doing it.

Psychologist Dr Juliane Kaminski, of Portsmouth University, studied what happens when a human forbids a dog from taking food.

Those left in a dark room who thought they could not be seen took more food and quicker than dogs in a well-lit room.

That suggests they take into account what the human can or cannot see.

Dr Kaminski said: “That’s incredible because it means 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.

"Humans constantly attribute certain qualities and emotions to other living things.

"We know that our own dog is clever or sensitive, but that's us thinking, not them.

"These results suggest humans might be right, where dogs are concerned, but we still can't be completely sure if the results mean dogs have a truly flexible understanding of the mind and others' minds.

"It has always been assumed only humans had this ability.

"The results of these tests suggest that dogs are deciding it's safer to steal the food when the room is dark because they understand something of the human's perspective."

She said that previous studies have shown chimpanzees 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".

The research, published in the journal Animal Cognition, studied 42 female and 42 male pet dogs aged one year or older.

They were chosen only if they were comfortable without their owners in the room, even in complete darkness, and if they were interested in food.