Seeds are also known as the reproductive organ of the plant. They have many ways of spreading their seeds. Some seeds grow inside fruits. Animals eat them and the seed emerges in their dung. Some seeds, such as nuts and grains, are gathered by animals and stored in larders. Others have tiny hooks which cling to the coats of passing animals. Dandelion and maple seeds are so light that they are blown by the wind. Some plants have seed cases, which 'explode' or split open, throwing seeds in all directions.