Instead of loud miaowing, and even howling, when your cat wants food (behaviour likely to have them sent packing from the bedroom), some cats disguise their cries for attention within an otherwise pleasant purr.

Ahhh, your Mog is sleeping yes?.... or is he secretly planning new ways to get fish suppers out of you? - The jury's out

The result, according to a study published recently in the journal 'Current Biology', is a "begging" purr with a high-frequency element that triggers a sense of urgency in the human brain. Owners find it irritating, but not irritating enough to kick the cat out, and feel driven to respond.

Dr Karen McComb, a specialist in mammal vocal communication at the University of Sussex, said that by employing an embedded cry, cats appear to be exploiting hidden tendencies that humans have for nurturing offspring.

She went on to say that - the embedding of a cry within a call that we normally associate with contentment is quite a subtle means of getting a response – and solicitation (begging) purring is probably more acceptable to humans than the usual meowing,.

McComb, whose usual subjects include African elephants and lions in the wild, began the research into domestic cats after noticing the "manipulative" purring of her own cat, Pepo. "I wondered why this purring sounded so annoying and was so difficult to ignore," she said. "Talking with other cat owners, I found that some of them also had cats which showed similar behaviour."

After testing human responses to different purring types, McComb and her team found that even those with no experience of cats judged the "solicitation" purr to be more urgent and less pleasant.

On examining the frequency of the special purr, she found a peak similar to that of a baby's cry, which gave it a "noisy, slightly whiny quality".

However, not all cats have the cry; the researchers, who examined 10 cats, found it only in those living in single-person households. "We found that cats learn to dramatically emphasise the peak when dealing with human owners that have a one-on-one relationship," McComb said.

Asked whether the cat's special purr is more effective than a dog's bark, or other demand for food, she said: "I think it might be more effective than a dog. If you ask people who own cats what they do when they get up they say they feed their cats. Even before they have a cup of coffee. Cats are very good at getting their own way."

(well this doesn't apply to our Norman for sure!) Ed.
.....but, er, come to think of it...