Coffee and cocoa aren't the only plants that produce caffeine. Some flowers contain the drug in their pollen, and while some researchers have suggested that caffeine might be beneficial to bees, new research adds doubt.

Past research has indicated that caffeine improves bee memory, not only allowing them to find the most optimal plants for pollination, but also enabling them to remember their routes so that they can better remember their way to the correct flower each time.

That’s good news for the worldwide collapse in the honeybee population, also known as colony collapse disorder, which the National Resources Defense Council (NRDC) reports has affected 42 percent of bee colonies in the United States in 2015 alone. The NRDC points to pesticide use as a major culprit.

But a new study points out that all that caffeine might not be as good for the bees as previously thought: Caffeine may enable them to be more efficient pollinators, but the bees keep returning to less nutritious flowers for their food each time.

Furthermore, plants that are aware of caffeine’s effect on honeybees may use traces of caffeine in their pollen in order to keep luring bees back.

"[S]ome plants, through the action of a secondary compound like caffeine that is present in nectar, may be tricking the honey bee by securing loyal and faithful foraging and recruitment behaviors, perhaps without providing the best quality forage," Dr. Margaret Couvillon, of the University of Sussex, said in a press release.

Dr. Couvillon’s fellow researchers warn that these pollinating behaviors could have serious consequences for bees.

Get the Monitor Stories you care about delivered to your inbox. By signing up, you agree to our Privacy Policy

"The effect of caffeine is akin to drugging, where the honey bees are tricked into valuing the forage as a higher quality than it really is," Dr. Roger Schürch, of the University of Sussex and the University of Bern, said in the release. "The duped pollinators forage and recruit accordingly."

“What I think it does is make them exploited pollinators,” Dr. Couvillon said. “The plants are tricking them into foraging in ways that benefit the plant, not the bee.”