The proboscis extension response (PER) has been used to study learning in a variety of insects, including bumble bees and especially honey bees. Can PER be applied in learning experiments involving other hymenopterans? Because of their lifestyle, it was predicted that the eusocial hymenopterans would be more likely to exhibit PER than less social species. Several species of bees and wasps, representing different levels of sociality, were tested by restraining the insect and then applying a droplet of 25% sucrose solution to an antenna to see if they would react by extending their proboscis. Only honey bees and yellowjackets consistently responded with proboscis extension. Few bumble bees and no communal or solitary bees responded. These results suggest that our ability to elicit the proboscis extension reflex in the laboratory may be influenced by the hymenopteran's level of sociality. However, our study does not preclude that innate species differences, level of domestication, or technique may be influential.