M-PETS Grow Rodent Grass brings the outdoors inside. DIY grass kit consisting of wheat, barley, and oat seeds. Easy to grow indoors. This is a DIY grass kit consisting of wheat, barley, and oat seeds. Rabbits and guinea pigs need a diet high in fiber and grass or hay. Why not spoil them and grow them in the comfort of your own home, knowing they are free from harmful chemicals or pesticides? Grass contains vitamins and folic acids and can assist in keeping both their gut and teeth healthy.