It turns out that, like humans, bees get a buzz when they drink caffeine, and it superchargers their long-term memory! That spurs them to return to the same type of plant. This boosts the plant's chances for pollination.
One flower that naturally produces caffeine, not surprisingly, is the coffee plant. But some citrus plants, such as orange and grapefruit, serve caffeine, too.
When scientist Geraldine Wright first learned that certain citrus plants had caffeine in their nectar she began to wonder. Why would a citrus plant produce caffeine? It's a compound that's quite "costly" for a plant to make. And the nectar is meant to attract bees - who actually eschew caffeine at high levels because of its bitter taste.
Wright gathered nectar from three species of coffee plants and four types of citrus. All of them, she found, contained very low doses of caffeine.
She discovered that the caffeine helped a bee remember that the flower's scent promises a tasty payoff. This makes the bee want to seek out those flowers.
Bees and other insects are crucial to the life of plants. Plant pollen sticks to their legs while they feed on a flower's nectar. They then carry the pollen to the next bloom they visit. This process is necessary for trees and plants to make fruit and seeds.
Flowers are instilled with a whole range of tools such as color, design and scent to attract pollinators like bees, hummingbirds, butterflies and more.
How could researchers tell that caffeine boosts a bee's memory? In an experiment that used lab tools instead of flowers, they trained individual bees to expect a sugary drink when they smelled a certain floral scent. Some bees got nectar-like concentrates of caffeine in their drink, while others didn't.
They later exposed the insects to the same scent and watched to see if they extended their feeding tubes in response, a sign they were ready to sip. After 24 hours, the bees that had gotten caffeine were three times as likely to remember as bees that hadn't. After 72 hours, they were twice as likely.
Quite impressive for an insect!