Fig. 3. An odor paired with stimulation of the antennae produces associative learning. Pollen foragers conditioned with forward pairing of the odor and sucrose stimulation of only the antennae demonstrated the most robust conditioning. Recall of honey bees receiving backward or unpaired conditioning of odor with antennal-only stimulation was significantly lower than that of the forward-paired subjects ( ²₂=7.45, P=0.024). The proportion of bees responding to the conditioned odor during two recall tests is shown (N_forward=22; N_backward=21; N_unpaired=23).