A father in southeast Australia threatened to keep custody of his children if he ever found more than 10 lice on their heads, a court has heard.
The man also took a jar of the critters to his children's school to complain what a bad mother his ex-partner was.
He then asked the Federal Magistrates' Court in Victoria for sole parental responsibility because his ex-wife neglected the children, who were "continuously plagued" with lice.
The unnamed man, 47, wrote his former partner a long letter detailing methods to get rid of head lice.
"If I ever again see more than 10 adult lice on either of the kids at any time they shall not be returned to you until ... you are able to demonstrate an ability to manage lice," he wrote.
He took photos of the severity of the infestation and claimed it greatly exceeded that of normal childhood.
The woman, 46, said her former partner was obsessed with lice and his behavior was causing distress to the children.
Federal Magistrate Evelyn Bender ordered the children stay in the custody of the mother and have no contact with their father.