Admit it, Effects of cocaine on honey bee dance behaviour (A.B. Barron et al.; 2008) sounds exactly like the type of thing you'd like to read about on a lazy Sunday morning — and it reports on exactly what you'd imagine. The authors decided to take a closer look at the discrepancy that is the destructive effect of cocaine as an addictive drug and its ecological role as a natural insecticide (it is a neurotoxin that protects the coca plant from herbivory), by checking what effect it has on forager honey bees. The bees are known to communicate the location of resources by performing elaborate dances. After they were treated by a small dose of cocaine, these dances became more common, proving that the bees overestimated the importance and abundance of the resources they found, and after they were taken off of cocaine, they exhibited withdrawal symptoms — just as humans and other mammals do.
The bees treated with cocaine didn't show hyperactivity in their actions or any motor skill deficiencies or increased reactivity (as was shown for mammals and other insects), but they did increase their communication in a social environment. Additionally, they went through Pavlovian training just as successfully as the control groups, but upon withdrawal of the cocaine exposure, their learned behavior suffered substantially.
The question that the authors were hoping to answer was why cocaine presents a rewarding experience to humans and other mammals, but also serves as an insecticide (this is known as the paradox of drug reward). The proposed answer relies on the fact that small doses do affect honey bees in a manner similar to that in which they affect humans, but the concentration of cocaine that occurs naturally in coca leaves is much greater than the doses used for this study, having the honey bees quickly ingest a toxic dose. Thus, the reinforcing properties of cocaine may be considered to be a side-effect of its neurochemical influence.