Clever boy! Sheep recognise faces. They self-medicate. They're clever, dammit...

Sheep are not so dumb after all. New research shows that they self-medicate when they are ill. They can also identify and remember faces, both human and ovine, distinguish between happy and depressed expressions, and tell one sheep's bleating from another.

Scientists have discovered that sick sheep can accurately self-medicate for stomach problems. When sheep were given food than made them unwell, they were able to select and eat the right cures for constipation and heartburn. "People learn to take aspirin for headaches and antacids for stomach aches... Is it also possible that herbivores write their own prescriptions?" ask the researchers.

They say that from prehistoric times, people have believed that animals self-medicate, but that until now it has not been clear whether sheep can spot medicinal compounds when ill.

In the research, published this week, lambs were given foods that led to mild ill health, and then given a choice of compounds known to ease the symptoms. The animals were able to accurately spot and eat the specific compound that would cure their ill. "This is the first demonstration of medicine preferences in animals," say the researchers from Utah State University.

Sheep have enjoyed an improvement in their public profile, thanks to Dolly the cloned sheep and Sean fromWallace and Gromit. Nevertheless they are widely viewed as stupid.

But according to neuroscientist Keith Kendrick, Gresham professor of physics at Cambridge University, this is not true. "We now have a fair amount of evidence that sheep are not dumb. In fact, they can be quite cunning in terms of getting in and out of things, and coming back and looking as if they never went out in the first place,"

Professor Kendrick and his team have been investigating the face and emotion recognition among sheep and will publish their findings later this year.

"It is a review of how sheep process faces and emotions. We have found that sheep can recognise both human faces and emotions, and emotional changes on sheep faces. They are also able to form mental images of faces. They can recognise at least 50 different faces, and remember them for a couple of years or more," he says. "They are quite sophisticated in their social environment. They know what a happy face looks like compared to an angry one."

Researchers at the French Behavioural Ecology Group have also found that ewes are able to recognise the individual sounds of their lambs, suggesting that baas, which appear to the human ear to be all the same, may be unique to each individual.

"Our results show that ewes and their lambs can recognise each other based solely on their calls," they say.

All of which raises the question why they allow themselves to be bossed around by one man and a dog.

FLYING SHEEP

From Monty Python's Flying Circus

(A tourist approaches a shepherd)

Tourist: Good afternoon.

Shepherd: Eh, 'tis that.

Tourist: Uh... those ARE sheep aren't they?

Shepherd: Yeh.

Tourist: Only, what are they doing up in the trees?

Shepherd: A fair question... It's my considered opinion that they're nestin'.

Tourist: Like birds?

Shepherd: Exactly. These sheep are laborin' under the misapprehension that they're birds... Witness their attempts to fly from tree to tree. Notice that they do not so much fly as ... plummet. [Baaa baaa ... flap flap flap ... whoosh ... thud]

Tourist: Yes, but why do they think they're birds?

Shepherd: Another fair question. One thing is for sure, the sheep is not a creature of the air. They have enormous difficulty in the comparatively simple act of perchin'.

[Baaa baaa ... flap flap flap ... whoosh ... thud]

Trouble is, sheep are very dim. Once they get an idea in their 'eads, there's no shiftin' it.

Tourist: But where did they get the idea?

Shepherd: From Harold. He's that most dangerous of creatures, a clever sheep ...