Insecticides are cropping up in honey samples from around the world, a new study finds, suggesting that bees and other pollinators are being widely exposed to these dangerous chemicals. The commonly used insecticides, known as neonicotinoids, are absorbed by plants and spread throughout their tissues. When pollinators collect and consume contaminated pollen and nectar, they can suffer from learning and memory problems that hamstring their ability to gather food and sometimes threaten the health of the whole hive. That’s a pressing concern because of the important role of honey bees and wild bees in pollinating crops, particularly fruits and vegetables. To get an idea of the extent of the threat to pollinators from pesticides, researchers in Switzerland asked their friends, relatives, and colleagues around the world to provide locally sourced honey. They found neonicotinoids most frequently in samples from North America, where 86% had one or more neonicotinoid, and least often in South America, where they occurred in 57% of samples. Globally, just over a third of samples had levels that have been shown to hurt bees, the researchers report today in Science. None of the samples had concentrations dangerous to human health. More than two types of neonicotinoids turned up in 45% of the honey samples, and 10% had four or five; the effects of mixtures are not known, but suspected to be worse. The team calls on governments to make more data available on the amounts of neonicotinoids being used in agriculture, which would help clarify the relationship between the amounts used by farmers and how much turns up in honey.