We have these two twin kids. One is Billy and one is Timmy. I am wondering if Timmy is sterile. Here is what i got- Timmy lost his umbilical cord at one or two months old; Billy lost his at 2 weeks old. Timmy's horns has not even begin to sprout; Billy has already has them about this long: l---------------------l. Timmy has already begun to do this weird tongue thingy; Billy has not. They were born around December 17th?? Could my Kiddo be sterile?? if so them we need to make sure when we sell them, that they know he is not sterile.