The chances of bees being exposed to high levels of pesticides are high, according to a recent study.

Researchers at Newcastle University and Trinity College Dublin found that this is because bees are attracted to nectar containing common pesticides. They also found that buff-tailed bumblebees and honeybees could not taste the three most commonly used neonicotinoid pesticides and so did not avoid them.

Exposure to pesticides of this kind could affect bee's fitness, according to previous studies.

"Bees can't taste neonicotinoids in their food and therefore do not avoid these pesticides. This is putting them at risk of poisoning when they eat contaminated nectar," Geraldine Wright, lead author of the study, said in a statement. "Even worse, we now have evidence that bees prefer to eat pesticide-contaminated food."

This pesticide  targets the same mechanisms in the bee brain that are affected by nicotine in the human brain.

In the current study, the the bees showed an affinity for food which contained pesticides: when the bees were given a choice between sugar solution, and sugar solution containing neonicotinoids, they chose the neonicotinoid-laced food.

The lab-based study also showed that the bumblebees ate more of the food containing pesticides than the honeybees, and so were exposed to higher doses of toxins.

Wright said this finding is concerning because it suggests that like nicotine, neonicotinoids may act like a drug to make foods containing these substances more rewarding.

"If foraging bees prefer to collect nectar containing neonicotinoids, this could have a knock-on negative impact on whole colonies and on bee populations," she added.

Pollinating insects, like bees, are important for increasing crop yields - they are worth billions of dollars per year globally. When pollinating crops, they can be exposed to pesticides in floral nectar and pollen. Several controversial studies have shown that neonicotinoids have negative effects on bee foraging and colony fitness. As a result, public concern has grown over the impact of neonicotinoids on bees and other pollinators. In April 2013, the EU introduced a temporary ban on the use of neonicotinoid pesticides on flowering crops, while further scientific and technical evidence was gathered.

The findings are detailed in the journal Nature.