Some female dragonflies go to great lengths to avoid sex—they fake their own deaths.

For the first time, a scientist has observed that female moorland hawker dragonflies freeze mid-air, crash to the ground, and lie motionless when faced with aggressive males.

Called sexual death feigning, this behavior evolved to protect females against aggressive males; for instance, female moorland hawker dragonflies risk injury and sometimes death if coerced into mating. (See more examples of animals that play dead.)

Only five species, including a spider and praying mantis, are known to practice sexual death feigning, making this new discovery all the more intriguing, says Rassim Khelifa, a biologist at the University of Zurich who published a new study on the phenomenon in