Correlating ultrasonic communication with behavior in a small-scale rat colony living in a naturalistic habitat

Traditional studies of rat communication have focused on a few individuals in simplified laboratory settings, leaving colony-level vocal-behavioral dynamics largely unexplored. Here, we examined the nocturnal lives of a rat colony housed in an enhanced naturalistic habitat (ENH). Using infrared cameras and ultrasound microphones, we recorded 18,412 ultrasonic vocalizations (USVs) alongside social behaviors. Analyses revealed structurally distinct USVs not previously characterized statistically or behaviorally. Notably, 22 kHz calls-typically associated with aversion-occurred across multiple social behaviors lacking obvious aversive context. Brief exposure to cat hair elicited uniquely modified 22 kHz calls as rats fled to their burrows, remaining hidden for two days. The introduction of an unfamiliar caged rat, and the disruption of the colony's social structure then showed how social stressors alter vocal-behavioral dynamics. These findings reveal the structured and context-sensitive nature of rat vocal communication, establishing the ENH as a powerful model for studying social-vocal behavior.