These wood treats with a crunchy bark crust encourage chewing behavior that promotes healthy teeth and gums for hamsters, gerbils, mice and other furry friends. All-natural. Prevents overgrown incisors. No artificial colors or flavors.Now you can provide your pet with a clean, sanitary supply of Bark Bites and a natural chewing activity.Hole in center for each for use on Critter Ka-Bob or Bunny Ka-bob.