It's Pollinator Week, so how about celebrating with a toast to the bats that provided you with Margaritas! Tequila is made from Agave tequilana, a spiky, squat, blueish plant. It grows best in semi-arid soils, making it a great cash crop for marginal lands in Mexico.

Agaves are chiropterophilous; a fancy way of saying they're bat-pollinated. These plants and their pollinators have shaped each other through coevolution. Blooming agaves grow a stalk up to 15 feet high, with candelabra-shaped flower clusters at the top. The flowers only open at night and smell like rotting fruit, signaling bats the nectar bar is open. As they swoop in for a drink, bats get dusted with agave pollen, which they transport from plant to plant as sexual surrogates.

Agave nectar can be up to 22 percent sugar, and the pollen is 50 percent protein. The sugary treat keeps the bats fueled for flying, and leftover pollen is consumed when bats groom themselves. Multiple bat species pollinate agaves, and several migrate, following the bloom of agave and cactus through central Mexico to the Southwestern U.S. and back.

The BBC recently aired a wonderful documentary about the "Bat Man" of Mexico, Dr Rodrigo Medellin. Medellin has spent decades working to conserve the migratory "Tequila Bats" of Central America. This trailer gives you a close up look at the pollinating bats in question. And they are ADORABLE.

How do you make tequila? First, you get a whole bunch of blue agave plants, and a lot of really wicked-looking sharp utensils.

Is tequila cultivation bad for bats?

If you watch the tequila manufacturing video, you may notice a problem. Cultivation of agave for tequila involves actively preventing the plants from flowering. The harvest kills the plants completely. If there aren't any flowers, and all the agave plants are regularly killed to make booze, how do tequila pollinating bats get enough to eat?

In the video, Don Julio Tequila's plantation manager says he planted 1,700,000 agave plants that season. Propagating agave doesn't require seeds; the plants can reproduce vegetatively by sending out little plantlets underground. If no bats are around, the plant can also produce clonal "bubils" from unfertilized flowers. Not a lot of agave is grown for seed, and that means not a lot of cultivated agave is flowering.

Both the Mexican Long-Nosed Bat, the primary pollinator of agave, and its relative the Lesser Long-nosed Bat are considered endangered species in the U.S. The corridor of blooming plants their migration once followed is now fractured into private farms and paved roads. Native plants like the agave that can fuel their journey are less common. These bats also keep their babies in cave crèches with thousands to hundreds of thousands of bats in a colony. Stashing all their children in one place makes them especially vulnerable to disturbance from miners or drug runners seeking shelter.

As cultivated agave becomes more genetically uniform because of inbreeding, pollinating bats may be valued once again, and practices may change. It's certainly true that bats helped make agave the plant we grow and enjoy today. Here are two Smithsonian scientists discussing the biology of pollinating bats and their linkage to agave. Millions of years of evolution to bring you a fruity drink.

¡Salud!