Your younger brother observes some mosquitoes sucking juices of cut fruit pieces

Your younger brother observes some mosquitoes sucking juices of cut fruit pieces, though it is common knowledge that mosquitoes suck blood of humans. How will you explain this behaviour to him?

In many species of mosquitoes, males feed on fruit juices of cut fruit pieces while the females need highly nutritious food in the form of blood in order to be able to lay mature eggs.