Four people have been charged after police learned that children at a New Hampshire day case were being dosed with melatonin. The substance is often used to enhance sleep. The Manchester Police Juvenile Division said the arrests came after a lengthy investigation, Manchester police said in a statement on Facebook. “In November 2023, detectives received a report alleging unsafe practices going on in an in-home daycare at 316 Amory Street,” the statement said. “Through the investigation, police determined that the children’s food was being sprinkled with melatonin without their parent’s knowledg…