London: A team of researchers in Japan has observed that a female small copper butterfly adopts a simple way to avoid sexual harassment from persistent males - they close their wings.
By folding away their bright, striking wing patterns, the females make themselves less visible to males.
Lead researcher and butterfly lover Jun-Ya Ide from the Kurume Institute of Technology in Fukuoka had noticed that female small copper butterflies often closed their wings when other copper butterflies flew very close to them.
"I also found that she closed the wings at a lower rate when other butterfly species flew nearby," the BBC quoted Dr Ide as saying.
"Persistent mating attempts" from males can harm the delicate females, so Dr Ide thought the females might close their wings as a harassment avoidance strategy.
Virgin females, on the other hand, left their wings open.
"So, I concluded that, since females don``t need more copulations, they close their wings to conceal themselves," Dr Ide said.
Whereas virgin females that want to mate "keep their wings open to be conspicuous".
"The wing closing behaviour has evolved," he said, "to avoid sexual harassment."
The study has been published in the journal Ethology.