Scientists in Japan have observed that butterflies have a simple way to avoid the unwanted attention of males - they close their wings.
In the fleeting existence of the female small copper butterfly, sex is a one-time event, the BBC reports.
The Japanese team used a model of a male butterfly to study this behaviour. When they brought the fluttering model close to a female that had already mated, she folded up her wings.
But the females that had yet to find a mate left their wings open with their conspicuous wing patterns on display for passing males to spot.
The butterflies seem to have evolved this subtle strategy to allow them to hide and avoid what the scientists referred to as sexual harassment.
The findings have been reported in the journal Ethology.