Many plants use animals to disperse their seeds. Some plants grow fruits with seeds inside. When animals eat these fruits, the seeds go through their digestive tracts and are later excreted elsewhere, where they can grow into new plants. Other plants have seeds attached to burrs which stick in the fur of animals. These burrs later fall off, dropping the seed with them. Some plants benefit from hoarders like squirrels, which bury their seeds. If those seeds are forgotten, they can grow into new trees.
Many plants use the wind to disperse their seeds. Dandelions and other wind-dispersed plants grow tiny seeds, attached to parachutes or wings. When a gust of wind blows through, the seeds detach from the plant and float out to other locations. Some plants actually shoot their seeds some distance away. Lupins, pea plants and others have pods which suddenly burst open, scattering seeds.
Water is another means of seed dispersal. Plants such as coconuts, which often live near water, as well as many aquatic plants have seeds which can safely float, relying on currents to transport them to a new location.
Some seeds disperse only in extreme conditions. Jack pines have serotinus cones, which can only be activated by fire. When a forest fire burns down a tall, old Jack pines, the cones open up, ensuring that a new generation of Jack pines can grow after the fire dies down. This is a useful strategy, since pine trees have extremely long lifespans and only need to reproduce when the older pines are destroyed.