Tenants not getting along

[Albert Johnson]

I have two tenants that live in units next to each other. One tenant is complaining that another tenant is having other people over that are not on the lease and stays there. They told me everytime we come they leave before we get there. They rant about how they have to do a background check but other tenant has other occupying people there.

we also have a a small road that leads up to the properties. Its owned by us. The same tenant complains the other tenant is driving too fast.

These 2 don't like each other. There has been other minor incidents as well.

How do you handle accusations of others supposedly staying there, speeding, and disagreements?