The Pollen Wall is one of the hardest biological substances produced on earth. This is why Pollen is preserved in fossils and archeological sites. This protects the Pollen Grain during its transport to the ovule. Pollen is rich in protein and some animals like certain Bats are pollen eaters. This leads to cross-pollination.
Bees also collect pollen.
The Pollen can be seen on the hind legs of bees. Bee gathering Pollen from Anemone sp. Some erect Cacti produce large flowers that can be detected by Bat radar. The Bats visit these flowers at Night when they are Open and harvest the abundant pollen produced by the numerous stamens of the flowers. Some Pollen Grains have bladders or wings which help them float on air currents.