Two of my neighbors got gifts of puppies from another neighbor that the dog had many puppies. One of them could not find her puppy and saw a neighbor with a puppy that looks exactly like hers and she and the other neighbor started to argue. An old man came and asked them, "do you have a receipt?" The puppies were not bought so there was no receipt but they both described exactly same kind of puppy. Then the old man said, "they must be identical twins then". What a way of knowing the right owner of identical puppies?