Colonies of ants and bees -- already some of the most efficient and industrious workers in the animal kingdom -- depend on female workers for their success, according to a new study.
These effective and altruistic workers in social insect colonies are more likely to be female because their maternal instincts make them more suitable for caring for the colony queen's offspring, the researchers from University of Edinburgh said in a statement.
"The findings come from a study of who does what in these highly organized insect societies. In these species, it is only females that raise the colony's young. This is in contrast to other insect groups, such as termites, in which both males and females lend support," the researchers wrote.
This behavior was once only attributed to ants because the females in the colonies are more closely related to the queen than in other social insect species. But further research has revealed that colonies of bees and wasps have highly effective females workers as well.
For a long time, this behavior in ants was attributed to the insect's unusual genetics, where females are more closely related to their sisters than other relatives.
But it turned out genetics alone could not strange this behavior.
Instead, males and females were found to take on jobs to which they are best suited historically. In ants, for example, females are the main carers and have evolved from species in which mothers did most of the parenting.
The researchers suggest the study overturns an old theory that suggests there is an instinctive drive among insects in social colonies to help individuals with which they share genetic similarities.
"The best explanation for why females are more inclined to help in rearing the queen's offspring is that they are already equipped with maternal behaviors preserved through evolution. In contrast, males aren't usually involved in parental care, and so they don't have the skills required," said Laura Ross, of the University of Edinburgh's School of Biological Sciences.
The research was conducted by the Universities of Edinburgh, Oxford and St Andrews and Auburn University in the US.