Private reminder
You can tell the parents privately that the sound insulation of the building is not good, and it will be very affected if the child runs downstairs.
Direct home reminder
Children can be reminded directly when they run around. Talk about the seriousness of the problem in front of the child and tell the child that the last reminder has made progress. I hope to make persistent efforts and do better.
Praise the children.
If the child has made some progress and the number of running around is obviously reduced, you can praise the child loudly when playing with other children downstairs. He said that he was very sensible and knew that there were old people living downstairs, so he didn't run around and make noise at home, which affected the rest of the old people. Everyone should learn from him.