“The failure of a landlord to provide such conditions can lead to violation of the law and impose civil and, at times, even criminal liability upon the landlord”.Please read up on your local laws as relates to landlord obligations for habitable premises.This to me is a no brainer and am sorry am not trying to be mean to you.You inform tenant of your duty which his really to their advantage and then you go in and address.If tenants want to prevent you from treating, then suggest that they provide you with suggestions for pet friendly/kid friendly pest control to use and suggest that you will attempt that for a short period of time to see if it works but in the end, if it does not you will need to come in with a different approach, different product to address the situation.If said tenant continues to fight you on the issue, I suggest moving to contacting an attorney about providing a notice to comply or quit possession.You are running a business here.The unaddressed rodent activity is only going to get worse because you have a tenant that is difficult.Document your approach to resolve and try to have them chime in with their own suggestions on the agreement that if it does not work you will have no choice but to use an alternative.I would then start working on rethinking that lease term as that there sounds like a tenant that will bring you trouble.You have a legal duty and if a tenant is keeping you from completing it, that there is a problem as the same tenant will turn around and make false allegations and/or accuse you of not addressing the issue when all along you have been trying to do just that.Be the boss here, it is your property.This is like a grown kid that wants to test your limits, I suggest you put an end to that nonsense as life is too short and you have too much else to do than allow your time to be wasted by stubborn tenants.Side note:Glue traps – so cruel and gross.Peppermint has worked well for me too as @Marci Stein suggests. 

Be stubborn.

And no its not illegal people settle all the time for back homestead taxs, I just haven't done it before in this county and they are being stubborn.

The lender is stubborn and has told the seller that they will not budge on the back payments. 

I’m either dealing with a stubborn seller or a shady seller’s agent/broker.

There's a few reasons this could be:-The price is too high and the owners are stubborn negotiators-There may be something wrong with the property-The local market has too much supply and not enough demandIf you think the property has potential, why not go check it out?

Some people are stubborn and refuse to let go of toxic things.

To be successful – you need to be persistent and kind of stubborn.

Unfortunately, he is extremely stubborn, and will not. 

And since I’m particular (ok, a bit stubborn) about the quality of workmanship (doing it all myself), we’re averaging about two years or so per flip.