A new research has shown that female dung beetles use their horns to fight competitors for collecting cow dung and breeding sites.

The new research by Nicola Watson and Leigh Simmons of the University of Western Australia, Perth was published in the New Scientist.

They studied female beetles fighting each other for dung which is a valuable source of nutrients for their eggs. Ms. Watson has said that parts such as horns or antlers are generally used by males to protect territory or win females but female rarely show such behavior.

They say that the need for this biological weaponry arises in the breeding ground where beetles with bigger horns could threaten opponents. The female beetles with bigger horns were able to collect more dung for its eggs.

They usually make balls of cow dung or brood balls and bury them in the ground for their young offspring. Then they lay an egg into each ball where it develops, hence more dung there is more fertile the offspring will grow to become.

"Larger-horned females managed to get greater access to the dung and reproduce more brood balls and in turn more offspring," said Watson.

The female beetles have a competitive life. They have to collect the dung quickly as it looses its usability very quickly.

Female beetles are also found stealing dung, raiding other brood balls, and replacing eggs with their own. Ms. Watson said that the intense rivalry between females have caused the horns to have evolved.