Escape is a life critical defensive behaviour. One potential escape strategy is using ultrafast movements to relocate quickly. These movements do not rely solely on muscle activation and are beneficial for ectotherms at low temperatures when muscle performance is constrained. However, the functional significance of ultrafast motions is often assumed. Here, we show with high-speed videos that Astraeus jewel beetles (Buprestidae) rapidly open their elytra to flick themselves into the air and the movement is of comparable speed to other known ultrafast movements. Our calculations indicate that it is likely a power-amplified mechanism. Behavioural trials and thermal imaging demonstrate that Astraeus beetles can flick at >
15°C lower body temperatures than walking or flying, suggesting that the behaviour could provide a significant survival advantage at low ambient temperatures. Taken together, we reveal a novel ultrafast movement and show its potential functional value in escape.