Happy Cat Sprout 'N Grow Greenhouse by DuneCraft. Watch your cats roll over, purr, and leap with excitement! Fresh catnip causes a strong reaction among cats. If you crush the foliage of this herb, it releases oil that attracts cats. In fact, cats will rub up against the foliage themselves to bruise it and release the scent. Catnip is also said to attract good luck. Safe for ages 4 and up.