i would say thats frustration LancsUK. ive seen a variety of types that were yappers have to admit whippets seem to have that trait including my old boy on rabbits but never on fox preban hes about 10 now so been a while. and heard of a good few that were jusst past around or shot these are usually in my experiance keepers who buy in grown dogs doing the job take it out once a week out of the kennel then the catch rate starts to drop and not after long the dogs there running lose all there muscle mass and are running completely unfit then they hear the yap yap of frustration and BANG or pass i