Researchers have found that neonicotinoids, a pesticide derived from nicotine, may be getting bees addicted to their toxin.

Neonicotinoids are applied to seeds before they are planted and are then dispersed throughout the entire plant as it grows, including the pollen and nectar. One recent study showed that wild bee colonies who feed on nectar containing neonicotinoids had difficulty growing and reproducing. Solitary bees also failed to reproduce under these conditions, though honey bees showed no sign of impairment.

Another study was conducted to determine whether bees are able to detect (and therefore avoid) the neonicotinoids. Bees were placed in a box with two tubes of sucrose syrup, one laced with neonicotinoids. Scientists expected the bees to either not be able to tell the difference between the two, or, if they could, favor the pure syrup. Instead, they were shocked to find that the bees liked the laced syrup better.

It’s unclear why bees like to eat this pesticide, though some have guessed that small doses of neonicotinoids may affect bees similarly to how nicotine affects humans. Bees may have formed addictions to the drug, though further research must be conducted to confirm whether this is in fact the case.