Tenants moved in their parents without permission or discussion.

[Aubrey Ford]

I have a one bedroom apartment I rented out to a nice couple back in June. Last Monday they informed me that his parents are staying with them for a "few days" It has been a week and they have failed to offer any end date. Based on the story they told me it sounds like the parents are effectively homeless and I suspect they have simply moved them in without permission. I have expressed my discomfort with them staying more than a week. I'm not certain how to address this. Unfortunately the lease is a month to month verbal agreement. I did send them a written lease ofr signatures before the parents showed up, but they have not signed the lease yet. Can I have the parents trespassed? or do I have to go through an eviction process of my tenants... . anyone been through anythign like this?