Well, besides your toes and fingers...
I agree with awfranklin, but Kongs can be a bit expensive...especially for 11 puppies! (:
Try NylaBones. They're the best for the pups teeth and come in many sizes and flavors. Plus, they can't chew off big chunks to get choked on like they can with rawhide. Rawhide is not good for dogs of ANY age. Rawhide can't be digested very easily so it stays in their system a long time. It can cause tummy upset and even blockage if fed too much rawhide at any given "chewing session."
Good luck and congratulations on your beautiful puppies! (: