Rassim Khelifa, an entomologist from the University of Zurich, Switzerland and the study's author, first observed this phenomenon in 2015 when he was collecting larvae in the Swiss Alps.
He watched a male moorland hawker dragonfly (aesna juncea, if you were interested) chasing a female for a long period of time.
Suddenly, the female spiralled to the floor, and stayed there motionless on her back
The male hovered above the female for a couple seconds and then left.
I expected that the female could be unconscious or even dead after her crash landing, but she surprised me by flying away quickly as I approached.
The question arose: did she just trick that male? Did she fake death to avoid male harassment?
Female moorland hawkers, unlike other species of dragonflies, aren't protected by their male mates when they lay their eggs, leaving them vulnerable to harassment.
Because her eggs can be fertilised by just one sexual encounter, mating again right afterwards could potentially damage their reproductive systems.
Khelifa nevertheless was surprised, as he had never observed this behaviour in all his ten years of studying dragonflies.
In the next 72 hours, he observed 27 out of 31 females plummeting to their fake deaths, with 21 of them being successful.
According to Adolfo Cordero-Rivera at the University of Vigo, Spain, this strategy is probably only common in dragonfly-saturated areas, due to the risky nature of the high-speed plunge:
Females may only behave in this way if male harassment is intense.
Extreme sexual conflict resolution, indeed.
According to Khelifa, feigning death to avoid sexual harrassment is almost unique: this would probably be “the fifth in the animal kingdom after a nuptial gift-giving spider, two species of robber fly, and a European mantis".
On the other hand, playing dead to avoid being attacked or eaten by predators has been observed in many animals species, including dragonflies.
It's likely that females expanded its use to overcome male coercion.
So the next time some young whippersnapper is getting just a little too aggressive with his grinding, you might want to consider falling on the ground and playing dead.
Hey, it might freak him out, but it beats making like a preying mantis and devouring him headfirst.