Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant later enabling fertilisation and the production of seeds most often by an animal or by wind. Pollinating agents can be animals such as insects for example beetles or butterflies; birds and bats; water; wind; and even plants themselves. Pollinating animals travel from plant to plant carrying pollen on their bodies in a vital interaction that allows the transfer of genetic material critical to the reproductive system of most flowering plants. When self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species it can produce hybrid offspring in nature and in plant breeding work.