After a long day buzzing between flowers, even the most industrious worker bee could use a little help remembering which ones she wants to return to the next day. Some plants have a trick to ensure they end up at the top of the list: caffeinated nectar.
A team of researchers bombarded honeybees with floral smells paired with sugary rewards, some of which contained the same levels of caffeine found in the nectar of coffee and citrus flowers. Three times as many bees remembered the odors associated with caffeine after 24 hours as they did the scents associated with sugar alone, the team reported in the journal Science. When the researchers applied the stimulant directly to honeybee brains, it had a positive effect on the neurons associated with the formation of long-term memories.
Now, they want to see if bees go out of their way to feed on caffeinated nectar, perhaps even ignoring predators to do so — behavior that, if observed, might shed light on the neurological processes behind addiction.