Distributed acoustic sensing reveals urban rat dynamics through environmental intelligence of dark fiber

Abstract Monitoring cryptic urban wildlife is critical for managing challenges to biodiversity, infrastructure, and public health. Here we repurpose an unused dark fiber within an active telecommunication cable, transforming it into a dense network of thousands of vibration sensors to continuously track Norway rat (Rattus norvegicus) activity. Our study focused on a 20-kilometer section of the cable, collecting vibroacoustic data from an 810-meter segment within an inaccessible urban tunnel in China over 39 days in 2021. We show that rat nightlife is shaped by the weather; their bimodal nocturnal activity was suppressed by high wind speeds, cloud cover, and temperatures exceeding their thermoneutral zone. The system also captured fine-scale individual movements and intricate social chase dynamics. Our findings demonstrate that repurposing existing fiber-optic infrastructure provides a scalable approach for high-resolution surveillance of hidden urban wildlife, offering new opportunities for urban management and sustainability.