Lateralized and bilateral sensory mechanisms independently regulate sociability and social preference in Drosophila

Social behavior involves sociability-the drive to interact-and social preference-the choice of partners. Using FlySocialer, an automated system for tracking group interactions, we analyzed male Drosophila melanogaster and found highly individualized, non-random social behaviors. Compared to randomized controls, flies showed stable individual differences in sociability and distinct partner preferences. Sociability exhibited a sensory-specific lateralized asymmetry: visual inputs via the left eye modulated interaction number, while olfactory inputs via the left antenna influenced interaction duration. Conversely, neither sensory manipulation exerted a significant effect on social preference. These results reveal distinct mechanisms for sociability and selectivity, highlighting lateralized sensory drive versus bilateral integration as core principles of social behavior in Drosophila.