Why would anybody do this? Renters who did not pay their rent solitary the place to their...

Renters who did not pay their rent solitary the place to their own fleas and cockroaches. In cleaning the house, I discovered they'd coated the entire floor and drain of the stall shower with concrete, and stuck a screw driver adjectives into the drain. Obviously it was done some time ago, not because they be mad at me or even believed I'd evict them. What's the purpose of this?
There is a horrible smell coming out of...
Answers:    This is zilch new. I hold had them pour flour and rice down the toilets, the drains etc. Then flush the toilets and put stuff on the handle so they run, turn all the faucets on, etc.
One guy forgot, I be storing his PC and portable gym for him, I still have it.

The subsequent time insist on heavy deposits and up front and insurance.
Go surrounded by every month and inspect, I insisted on it. Make sure what is broken is fixed right now. Keep up on everything.
My mobile home garden tub is leak AROUND...
Because some inhabitants are total jerks. I've be a landlord for 22 years and I've see it all. Your best insurance is a hefty deposit and a contract that allows you to periodically inspect the property. It take a special personality to be a tenant. Good luck.