You may have noticed that a cat about to pounce
on its prey will sometimes sway his head from side to side. Why does he do this? According to Desmond Morris this is to help precisely pinpoint the exact distance and location of his victim. Because the cat’s (and our) vision depends on the integration of the two images taken in by our two eyes, this slight motion helps him see more exactly – a critical element when hunting a very small being, and when, as is often the case, one shot is all you get.