<Tr> <Td> </Td> <Td> This article needs additional citations for verification . Please help improve this article by adding citations to reliable sources . Unsourced material may be challenged and removed . (December 2010) (Learn how and when to remove this template message) </Td> </Tr> <P> Counting sheep is a mental exercise used in some cultures as a means of putting oneself to sleep . </P> <P> In most depictions of the activity, the practitioner envisions an endless series of identical white sheep jumping over a fence, while counting them as they do so . The idea, presumably, is to induce boredom while occupying the mind with something simple, repetitive, and rhythmic, all of which are known to help humans sleep . </P> <P> Although the practice is largely a stereotype, and rarely used as a solution for insomnia, it has been so commonly referenced by cartoons, comic strips, and other mass media, that it has become deeply engrained into popular culture's notion of sleep . The term "counting sheep" has entered the English language as an idiomatic term for insomnia . Sheep themselves have become associated with sleep, or lack thereof . </P>

Where did counting sheep to sleep come from