Domestic pigs can quickly learn how mirrors work and use them to find food, scientists have discovered. What level of intelligence this indicates is a matter for debate. On the one hand, researchers could not say whether the pigs could recognise themselves in a mirror – the marker of self-awareness and advanced intelligence.

On the other, they didn't turn around, look over their shoulders and say, “Does my bum look big in this?” – the marker of a species with far too much self-awareness and advanced stupidity.

The study, undertaken by researchers at Cambridge University and published in the journal Animal Behaviour, introduced pigs to mirrors and allowed them five hours to get used to them.

After this amount of time, eight pigs were penned with mirrors angled to reflect food including M&Ms on the other side of partitions. Seven of the pigs had obviously worked out how mirrors worked, as they went straight behind the partitions to the food. It is understood the eighth pig was more of a Maltesers fan.

The pigs' failure to go on from there and pass the self-recognition test might have had more to do with the nature of the test than the nature of the pigs. The test – which dolphins, magpies, elephants and apes have passed – involves placing a mark on the animal's face. The animal sees the mark in the mirror and pokes at the relevant point on its face to try to remove it.