IMO, if you go out and yell at them etc they will find it funny and keep coming back. I'd go to the school and report it there saying how distressing it is to you when they do that.
Done nothing yet, waiting for some great ideas here

IMO, if you go out and yell at them etc they will find it funny and keep coming back. I'd go to the school and report it there saying how distressing it is to you when they do that.
a solution would be wire the bell to the mains.
soak them in water
Offer them sweets and ask them in......... wait...
Report them to the school.
You seem angry about it.
Do you go outside & shout at them?, as doing this is why they keep coming back.
Some mornings, a group of school kids would ring my doorbell en route to school then run away at lightning speed.
I know who they are, as I have some CCTV images of them running away from my door.
What should or could I do about them?