The owner of an in-home daycare in New Hampshire and three of her employees are facing charges after they allegedly served melatonin to children without parents’ knowledge and consent, Manchester police said.

52-year-old owner Sally Dreckmann and her employees — 51-year-old Traci Innie, 23-year-old Kaitlin Filardo, and 23-year-old Jessica Foster — are facing ten counts of endangering the welfare of a child.

Police in Manchester, N.H. said they began investigating the daycare in November of last year, when they received a report of “unsafe practices” at the in-home daycare on Amory Street.

Police discovered that children’s food was allegedly being sprinkled with melatonin. According to WHDH, a spokesperson for the Manchester police said it’s an over-the-counter drug.

“But for it to be given to children without the knowledge or consent of the parents, it’s very concerning,” Heather Hamel said, the station reported.