The secretary calls on the second day if a child is out. The office calls, but not every day. As it turned out the child was sick and the mother was upset that I had been calling. I always know why a student leaves my class unless CPS is involved or there is strange situation, then I usually find out later. Children in placement homes move around a lot and we don't always know where they are going.
Administration sends an email if a student is suspended or sent home.
We have a truancy officer. Our attendance office calls and after 3 days, they go to the house. My district has a social worker that follows up if a child is out. All absences are checked up on if we don't have a reason. One mother had taken her child into hiding from the father.