Cats want 'living food' so supply kitty with CAT GRASS (WHEAT GRASS). It provides them with essential vitamins for skin and coat health; strengthens immune system; aids in their digestion by adding roughage and preventing constipation; assists in evacuation of hairballs instead of them vomiting; and satisfies their cravings for grass. Yard grass is not digestible like wheat grass and may be toxic due to pesticides and fertilizer. Buy kits and grow it yourself. Starts to sprout in three days!