Socially isolated bumblebees display frequent antennation and close interactions compared to socially reared bumblebees*

Bumblebees are eusocial insects that must correctly give and receive social cues to function as a group. Newly eclosed bumblebees go through a nine day period of rapid brain development as they take on tasks within the hive. To probe how social interaction during this time affects later behavior we removed newly eclosed bees from the colony and isolated them for nine days. We observed the behavior of age-matched bees from extra-hive isolated and grouped rearing conditions and hive reared bees. We used SLEAP¹ to track posture and quantified the behavioral repertoire of bees in both individual and paired trials. We find broad behavior differences between isolated bees and their socially reared counterparts. We also find that isolated bees paired with any other bee (isolated, grouped control, or hive reared) have increased antennal interactions and prefer closer interthorax distances with their partner than socially reared bees.