should play in their own half of the garden!!
It cracks me up! I dont allow my own kids to even walk on their grass but they allow their kids and their friends to run up and down the whole lot playing football. 
I dont want to say anything cos i just know they will take offense but its right outside my living room window and a ball smacking of the wall is not good. I live in a semi detached and its got a square bit of garden at the front which is for both houses so aibu to expect them to respect my bit?
Grrrr Grrrr and Fuck