Two baby boys were lying on the floor.
It was only during another check of the home that assisting officers heard noises coming from a bedroom. That's where they found a 4-month-old girl hidden between a mattress and a wall.
"I must note that, if it was not for the alertness of the officers on the scene, that this 4-month-old baby probably would have died," said Lt. John Andrews of the Chicago Police Department.
The adults were taken into custody and charged with misdemeanors, but felony charges are possible. All three babies are healthy and are being cared for by relatives.