The vomeronasal system strongly influences social behavior, but it is unclear how complex semiochemical blends are represented during natural social interactions. We addressed this question by using head-mounted 'miniscopes' to visualize sensory activity in the glomerular layer of the accessory olfactory bulb (AOB) of freely moving mice. Imaging responses in second-order projection neurons, or mitral cells, during active investigation of conspecifics revealed combinatorial activity across multiple glomeruli, with patterns overlapping substantially for different partners. Relatively few glomeruli were differentially activated by sex, strain, and/or contact site on the probe animal. Stimulus selectivity was similar for both constrained contexts, where investigation was limited to either facial or anogenital regions, and in freely-moving social interactions. Interestingly, glomeruli selectively tuned to male and female cues were more strongly activated by facial and anogenital regions, respectively. While individual glomeruli show a wide range of selectivity, population activity readily distinguished features such as sex, although our data do not distinguish between distributed, population codes or selective ‘labeled-line’ pathways to downstream limbic areas. Finally, we find a mismatch between the long timecourse of sensory-driven activity, lasting tens of seconds, and rapid behavioral dynamics during investigation, where different body areas or partners can be sampled in under a second. These data suggest that the vomeronasal system modulates behavior by integrating information over extended timescales rather than mapping individual sensory events onto discrete behavioral responses. Imaging during social interactions should help expand our understanding of how the AOB encodes complex semiochemical blends to modulate behavior, including both basic biological categories like sex, and more nuanced information such as individual identity.