Yes and I have been wanting answers to this.
I have a soon to be 16 year old female cat. She is a Russian Blue. She has never had kittens and she sucks her nipples as if she was getting milk from them. She has a bag of skin under her belly but does not feel like it is full of milk. Has anyone ever heard of this before ? Is this a serious issue or should I just let it go, I mean she does this a lot and when she does it she purrs very loud so I know she enjoys it. In a way it is kind of funny but irritating at times too. Any answers ?