Do animals have belly buttons?

Stella (the cat) jumps from the couch to the floor, trots over to where Erin is and rubs herself on Erin's leg. Erin, down on her haunches, starts to pet Stella, and Stella rolls on to her back. Erin is stroking Stella's belly and gazing at her lovely fur. She out of no where poses the question - "do cats have belly buttons?" My mind starts to race, comparing the 50 cats I have had in my life, then I jump to dogs, then to calves. No belly buttons my memory is telling me. I pretty much freak out imagining all these animals with belly buttons, its just a creepy thought, and then think - how could I never have noticed this. "It has to be true," Erin says, "they have umbilical cords. How else do they get nutrients from their mother?" Cara says cats have inverted nipples - easy access inside the womb. We all chuckle. Erin is convinced they do, and starts to probe Stella's belly. We argue back and forth, Erin throwing out all her big biology major words. I say there is no fricken way they have a belly button - who cuts the umbilical cord. Erin gets her DNA studying, John Hopkins student, boyfriend, future husband, Dr. Nick on the phone. Dr. Nick says they have umbilical cords and he belives belly buttons too. I again get a visual of umbilical cords hanging out of a cat to her litter of kittens. I ask Dr. Nick, now on speaker phone, "so its like 6 tentacles just hanging out of the va-j-j?" Dr. Nick says yah. Erin says that the mother eats the cord. I am getting sicked out. In the mean time Kim (the computer addic) has pulled up a web site and is reading... It turns out cats are placental animals (as well as whales, elephants, armadillos, cats, dogs, sheep...), and do have a belly button. It is in the same area as humans, and is only just a slight scar, covered by fur. They are born in a sac, and have an umbilical cord. Go figure.