David Attenborough while walking in a park came across a really sorry looking duck, covered in slimy mud and mess, so he carefully picked it up and wiped it nice and clean with paper hankies before popping it back in the lake where it happily paddled off. A little strole further on and he finds another bedraggled duck in a similar condition, so he again carefully cleaned it up with the last of his hankies before plopping the cleaned up duck to paddle off.
Another hundred yards or so he comes across another messy duck, but being out of hankies he approaches a group of lads and asks them if they've got any paper towels, to which they replied, " if ya need to wipe ya'r arse mate just use a duck, its what we do "