Take for a start the sheeps' tendency to 'op about the field on their 'ind legs. Now witness their attempts to fly from tree to tree. 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'.
Trouble is, sheep are very dim.
Once they get an idea in their 'eads, there's no shiftin' it. And that's a depressing prospect for an ambitious sheep. Because of the enormous commercial possibilities if 'e succeeds. To the Monty Python Archive .