Ankle Bone

Jay: Mommy what's this? (points to his ankle bone)
Me: That's your ankle bone.
Jay: No it's not.
Me: Yes it is. See (I point to my own ankle bone) Mommy has an ankle bone and Jay has one too.
Jay: No it's not.
Me: Then what is it Jay?
Jay: A dog bone.

So I guess there is more to boys than just puppy dog tails. Apparently they have some puppy dog bones as well.