During a rest period for a group of children who are younger than 2 years old: The required staff/child ratio applicable to that group shall be maintained; and Each staff member assigned to the group shall remain with the children. During a rest period for a group of children who are 2 years old or older: The required staff/child ratio applicable to that group shall be maintained until all the children are resting quietly; and Once all the children in the group are resting quietly: At least one child care teacher or aide assigned to the group shall continue to remain in the room with the children; and Other staff members, if any, assigned to the group may leave the room but shall remain on the premises and within hearing range.