What makes mice freeze or flee

Mice are likely to freeze at the sight of small slow-moving shapes and flee from fast approaching ones, finds new UCL research. This provides the first evidence that mice make instinctive behavioural choices based on vision alone, and could help inform future studies of behaviour and brain function in mice. Knowing how mice instinctively respond to visual cues will enable researchers to conduct easy, reproducible studies to see if this behaviour is disrupted in mental and physical conditions. The study, published in Current Biology, involved mice that were shown visual stimuli in a controlled environment while their movements were filmed. The environment included open ground, a covered refuge and a display screen representing the 'sky'. Small discs moving slowly across the screen simulated flying predators cruising at a distance, while growing discs simulated approaching, 'looming' predators. The results showed that mice fled to the refuge 88% of the time when they saw the looming disc, but instead froze 84% of the time when they saw the cruising disc.