Have you forgotten that the hoot-owl's hoot is used in the same manner? "I don't give a hoot about the man in your moon." "I don't give a rat's ass about ..." See? Same idea. Owls get picked on, too. Maybe our choice has less to do with a specific animal and more to do with the way the phrase "rat's ass" rolls off the tongue. At least that's my take. "Rat's" and "ass" together makes a complementary sound. Better than "porcupine's ass" or "ostrich's ass," anyway. The sharp "T" sound in mid-phrase keeps it from morphing into one big long noise, like "rrraaaaassssss". Helps to keep the two words, or two syllables, apart. All in all, "rat's ass" is a phrase that works, even if it does spotlight the already maligned rodentia. Let's not even get into the way "rat's butt" sounds. When I want to indulge in the "b" word, I throw the word "duck" up first. "I don't give a duck's butt who's calling. I can't come to the phone right now." "But it's the president. He needs your advice. Again." "Oh brother. He just doesn't get it, does he? I can't influence the other Answerbag members to change their low ratings on all his bad answers. I don't give a rat's ass who he is or how much he whines." While "duck" and "butt" don't exactly rhyme, they sound alike. It's a good combo. Plus the picture it conjures up of a duck's little yellow tail feathers sticking out as the imaginary duck waddles along, quack, quack, quacking makes me laugh. You know - quacks me up. I hope this sheds some light on the matter.

i could'nt give A William Shatner's ass about the hole thing!