How bats exit a crowded colony when relying on echolocation only - a modeling approach

Bats face a complex navigation challenge when emerging from densely populated roosts, where vast numbers take off at once in dark, confined spaces. Each bat must avoid collisions with walls and conspecifics while locating the exit, all amidst overlapping acoustic signals. This crowded environment creates the risk of acoustic jamming, in which the calls of neighboring bats interfere with echo detection, potentially obscuring vital information. Despite these challenges, bats navigate these conditions with remarkable success. Although bats have access to multiple sensory cues, here we focused on whether echolocation alone could provide sufficient information for orientation under such high-interference conditions. To explore whether they manage this challenge, we developed a sensorimotor model that mimics the bats’ echolocation behavior under high-density conditions. Our findings suggest that the problem of acoustic jamming may be less severe than previously thought. Bats can compensate for potential interference by emitting frequent calls with short inter-pulse intervals (IPI), creating a redundancy in the sensory information that allows them to aggregate echoes over multiple calls. This redundancy, combined with simple pathfinding strategies, such as following walls and avoiding nearby obstacles, enables bats to exit the roost effectively, even when faced with significant sensory interference. Our model indicates that bats’ echolocation strategies are robust enough to mitigate the effects of jamming and demonstrates the critical role of signal redundancy in successful navigation. These insights not only enhance our understanding of bat behavior but also offer implications for swarm robotics and collective movement in complex environments.