Does your puppy turn his nose up at his own chow-because he wants some of whatever it is that you 're having? A new study finds that, when it comes to food, dogs recognize human social signals about what's good. The work is in the journal Public Library of Science ONE. Researchers let pet dogs choose between two plates, one with a single piece of food and the other with six pieces. Unsurprisingly, the animals generally went for the larger portion. But when a human being showed a clear liking for the smaller plate, the canines likewise went for the skimpier choice. The dogs apparently recognized and responded to the humans ' social cues. And not all cues were equally effective. When the human approached but did not touch the smaller portion, dogs ignored the attention drawing gesture. For a social signal to influence behavior, it had to demonstrate intention. And the most effective cues also involved communication, such as looking from the food to the dog and back while talking encouragingly. For dogs, choosing a bite may depend on another's bark.