How one species of bat uses its tail to navigate backwards in caves

A new study from Tel Aviv University reveals that the greater mouse-tailed bat (Rhinopoma microphyllum) uses its long tail as a natural tactile sensor to navigate backward in dark caves. The researchers discovered that the bat’s long tail functions as a dynamic sensing tool, enabling it to avoid obstacles and orient itself in complex environments while climbing backward—especially when other sensory abilities like vision and echolocation are limited.

The study found that when the tail was numbed with a local anesthetic, the bats’ ability to navigate around obstacles while crawling backward and the speed of their movement decreased significantly.

The research was led by Sahar Hajyahia and Mor Taub, students in the laboratory of Prof. Yossi Yovel of Tel Aviv University’s School of Zoology in the Wise Faculty of Life Sciences and the Sagol School of Neuroscience. The study is published in the journal iScience.

Professor Yovel explains, “During the study, the bats crawled up a vertical maze while moving backward as we recorded their movement using an advanced tracking system. The bats used their tails like a blind walking cane, swinging them from side to side to detect obstacles and climb more safely and efficiently. In contrast, when the tail was numbed, the climbing time increased by an average of 10%, and the bats made more lateral movements instead of moving upward, apparently trying to find their way.”

The researchers also noted that the bats demonstrated a remarkable ability to distinguish between different textures using their tails. They were able to differentiate between a fine wooden grid (1 cm intervals) and a sparser grid (1.5 cm), highlighting the tail’s complex ability to serve as an exceptionally sensitive tactile sensor.

Professor Yovel concludes, “In most bats, the tail is very short and integrated into the wing membrane. In Rhinopoma, however, the tail remains long and free, and to the best of our knowledge, they are the only bats that use it to sense their immediate surroundings. This is another example of how evolution adapts animals’ senses to meet specific needs—in this case, moving backward in dark places around obstacles and other bats.

“Many bats crawl backward on dark walls and cannot use their frontal senses like vision and sonar to ‘see’ behind them. One can think of the tail as a sort of reverse sensor for the Rhinopoma. This discovery opens the door to further research on tail usage as a sensor in other animal species. Additionally, the findings could inspire the development of new sensory technologies inspired by nature, such as robotic navigation systems for complex environments.”