What types of animals do plants employ as pollinators? There are insects, of course: bees, wasps, butterflies, moths, flies of all kinds, even beetles. There are hummingbirds in the new world and sunbirds in the old. Some tropical flowers are pollinated by bats.
You can often deduce the natural pollinator of a flower by paying attention to its shape, color, and fragrance. Moth-pollinated flowers are white or green, often with long nectar spurs, and tend to be fragrant at night. Butterfly-pollinated flowers are roughly the same shape but brightly colored. Bird-pollinated flowers are tubular or bell-shaped, usually red or orange, and are generally scentless because birds depend on sight more than smell. Fly-pollinated flowers often smell like carrion or feces and may look like it too.
So, what pollinates the flowers shown above? They’re a dull brown, filled with thick, gelatinous nectar, have an odd yeasty smell, and sit on the ground.
Give up? Gerbils.
This is a gerbil-pollinated flower.
Massonia depressa grows in the arid Karoo region of South Africa. It is a winter-growing bulb that produces a single pair of large, fleshy leaves that grow flat on the ground. A study of plants growing in the wild  showed that the flowers attracted several species of rodents, including two species of gerbils and three species of mice. At least some of the mice ate the M. depressa flowers, but the gerbils fed exclusively on the nectar, never damaging the flowers but getting their snouts coated with pollen in the process.
M. depressa certainly isn’t the most beautiful species in the hyacinth family (Hyacinthaceae), but it is fun to grow as an oddity. My plant spends its summer dormancy in the greenhouse, bone dry from March until September. In late September, I put the pot outside and start watering. The plant stays outdoors until the first frost is forecast, whereupon I put it back in the greenhouse. It would probably tolerate some frost if growing in the ground, but I don’t want to risk the pot freezing. Back in the greenhouse, it usually flowers at the beginning of December. It is currently blooming on schedule.
Johnson, S.D., Pauw, A., Midgley, J. (2001) Rodent pollination in the African lily Massonia depressa (Hyacinthaceae). American Journal of Botany 88:1768-1773.