Learning and memory in honeybees is analyzed on five levels, using a top-down approach. (a) Observatory learning is applied during navigation and dance communication. (b) Local cues at the feeding site are learned associatively. (c) Classical conditioning of the proboscis extension response to olfactory stimuli provides insight into behavioral, neural, and neuropharmacological mechanisms of associative learning. (d) At the neural level, the pathways coding the conditioned and the unconditioned stimulus are identified. The reinforcing function of the unconditioned stimulus is traced to a particular neuron. (e) At the cellular level, the cAMP pathway is found to be critically involved. Nitric oxide is an essential mediator for the transfer from short- to long-term memory.