Purchase problems

A little old lady went to the grocery store to buy cat food. She picked up three cans and took them to the checkout counter. The girl at the cash register said, 'I'm sorry, but we cannot sell cat food without proof that you have a cat. A lot of old people buy cat food to eat and the management wants proof that you are buying the cat food for your cat.'The little old lady went home, picked up her cat and brought it to the store. They sold her the cat food. The next day she tried to buy three cans of dog food. Again the cashier demanded proof that she had a dog because old people sometimes eat dog food. She went home and brought in her dog. She then bought the dog food.The next day she brought in a box with a hole in the lid. The old lady asked the cashier to stick her finger in the hole. The cashier said, 'No, you might have a snake in there.'The little old lady assured her that there was nothing in the box that would harm her. So the cashier put her finger in the box and pulled it out and told the little old lady, 'That smells like shit.'The little old lady said, 'It is. Now can I buy three rolls of toilet paper?'