hey margaret,

it's beth. i was just looking for some science lesson plans for the fourth graders, and i found this:
Virtually all mammals have umbilical cords and hence navels. Cats navels don't look quite like humans, more like a scar really. But since they're hidden by hair and located just alongside their rib cage, it's quite understandable that they are often overlooked.

i'm sure you knew this already, but it's comforting to know so many people are asking this question.
love,
beth