A study by researchers at the University of California Berkeley has found that ethanol is surprisingly common in floral nectar, the sugary fuel that keeps pollinators alive. Yeast feeding on those sugars produces trace amounts of alcohol, and in this study, it showed up in 26 of the 29 plant species sampled.
We saw that it wasn't just neuronal changes that occurred during alcohol intoxication. When blood alcohol levels dropped to zero, when the hangover began, changes occurred that could sometimes be even higher.