As in many processes in nature, timing is important. The female reproductive part of a flower is receptive to pollen only at certain times of the year. Creatures like insects and birds, which move from flower to flower in search of food, are a fast and often guaranteed way for plants to distribute their pollen.
Both the male and the female reproductive parts of a plant are in the center of the flower. The male, pollen-producing part is called the anther, held aloft by a stalk called a filament. The entire male apparatus is called a stamen. Each pollen grain is unique to its species. The female reproductive part of a plant, the stigma, sits on top of a style, or stalk, which leads to an ovary at the base. The entire female plant mechanism is called a pistil.
How does the process of plant pollination by animals work? A pollinator (such as a bee, bird, bat, or butterfly) in search of food visits a plant. The plant has secreted nectar, a concentrated food source, from special glands and tucked it away in its blossom. While crawling around the blossom looking for nectar, the pollinator rubs against the pollen, which becomes attached to different parts of the pollinator's body. When the pollinator visits another blossom, it transfers the pollen grains from its body onto a strategically placed stigma. After it reaches the stigma, the pollen grain grows a tiny pollen tube down the style and into an egg-filled ovary. Eventually, the pollen and the egg form a seed.