Female frogs play dead to avoid unwanted male attention.
Researchers say the findings shed new light on the mating habits of the European common frog and suggest that females do not simply put up with the way males scramble for mates - a situation that can lead to several males clinging on to a female, sometimes with fatal consequences.
Dr. Carolin Dittrich, the first author of the study from the Natural History Museum of Berlin, said: "It was previously thought that females were unable to choose or defend themselves against this male coercion.
"Females in these dense breeding aggregations are not passive as previously thought."
The findings, obtained from 54 females who experienced the clutches of a male amphibian, found that tonic immobility - stiffening with arms and legs outstretched in a pose that mimics playing dead - occurred in 33 per cent of all female frogs clasped by a male.