Usually either Oatgrass, Barleygrass, Wheatgrass, or Ryegrass. In the pet store a suitable species will be labeled just "cat grass." You can buy seeds and you

Usually either Oatgrass, Barleygrass, Wheatgrass, or Ryegrass. In the pet store a suitable species will be labeled just "cat grass." You can buy seeds and you can buy it fully grown (and ready to eat)