Bees
When bees land on a flower, their feet often slip into a little groove that holds pollen sacs. When the bee flies away it carries off this sac like a saddlebag stuck on its feet. When this bee lands on another flower looking for nectar, the "saddlebag" falls off, the pollen falls out of the sac, and pollination is underway.
Wasps
Wasps, like bees, pollinate plants and flowers as they feed on nectar. If we were to eradicate all wasps it would cause more problems than it would solve. So, wasps do serve a purpose and despite being a problem at certain times of the year, they are a beneficial insect.
Birds
There are 2,000 bird species globally that feed on nectar, the insects, and the spiders associated with nectar bearing flowers. In the continental United States, hummingbirds are key in wildflower pollination. They thrust their long slender bills deep into the flowers for nectar, withdrawing faces dusted in pollen.
Bats
Bats feed on the insects in the flowers as well as on the nectar and flower parts. It is believed that the birds and bees take the day shift and the bats take the night shift. Everything that we know about pollination in the day time occurs at night with the bats.
Butterflies & Moths
When feeding on nectar from flowers, pollen will be deposited on their appendages and then transferred to the stigma of the next flower that the butterfly or moth visits to feed on.
Wind
Wind pollination also known as anomphily, is when the pollen is transported by weather rather than by pollinators. Many of the most important crops are pollinated by anomphily.