tenants quarrelled, what would you do?

[Yiv L.]

Two of my neighboring tenants in the 4-plex quarreled, caused by small kids from one family playing and making some messes on the other family's front yard (the complex has open front yard), then verbal exchanges from adults.

The family with small kids (7 and 8) just moved in over a month.

The other family (late middle aged with 3 teenagers) moved in almost a year, and are very good paying and quiet tenants. They do not like to be disturbed..

I talked to both families, but not sure how much it helped. I do not have any vacant unit to move them around. I know I am not peace keeper, but I suspect sooner or later, one or both tenants will break the lease and leave if it continues this way. Any suggestion?