What's Daddy for

"Mummy, where do babies come from? "The stork, dear."

"Mummy, who keeps bad people from robbing our house?" "The police, dear."

"Mummy, if our house was on fire, who would save us?" "The fire department, dear."

"Mummy, where does food come from?" "Farmers, dear."

"Mummy?" "Yes, dear?" "What do we need Daddy for?"