Redback Spiders love a deadly affair
FEMALE redback spiders eat male mates who do not spend enough time on foreplay.
To keep cranky females happy, their partners have to spend about 100 minutes on courtship, doing things such as vibrating their webs and rubbing their tummies.
But once the fickle babes are brought to a peak of amorous and receptive behaviour, they will let a stray male mate with them even if he hasn't done any courting at all.
If he's quick, he can do the business and then run off before she gets a chance to eat him.
Research by Maydianne Andrade and Jeffrey Stoltz of the University of Toronto in Canada found Australian redbacks chose males based on a courtship duration threshold.
If the first male did not spend enough time wooing the female, she would eat him before he had a chance to mate.
But they found that once the female's courtship demands were met, other males could take advantage of the efforts of the first male.
"Thus females apparently do not distinguish which male is the source of the stimulatory courtship," they said in Proceedings of the Royal Society.
"Females respond by limiting male mating opportunities with a severity that depends on courtship investment."
The scientists think their work may have clarified why clusters of males are seen around some females when other females remain uncontested.
Males may know they can do better with females if they stick together.
"Effectively, this means that there may be selection for smaller males or those in poor body condition to seek out, rather than avoid, competitive situations in nature," the researchers said.