My inspector didn’t note any serious issues besides the fact that the toilet was leaking into the crawl space.

Working with a PM that specializes in this area, we have a strategy that involves complete reno of units, combo of section 8/market tenants, getting rents to market and offering a quality living space that attracts better tenants. 

Ultimately it may be in your best interest to take care of it and may be required by law depending on the state.Rats don't squeeze in under a door, not a normal door at least, so I would first make sure that all outside cracks, crevices and holes are filled up, especially in a crawl space to prevent anymore from getting in.Then, again it really depends on the state laws, but after my due diligence is done sealing up the up the outside and inside of any places a rat could get in I would think about telling the tenant that they can buy rat traps or whatever they want to use to get rid of what's is inside and I will reimburse them the cost with a recipe, I would only do this if I felt comfortable with local laws otherwise I would just hire a pest control person to take care of it.

Just kidding I know it isn’t complicated but how do you figure if the numbers are right ?

Not enough space here for the explanation, however I will tell you that it involves what Einstein referred to as the "greatest invention of the 20th century"....compound interest.

It could also present an opportunity to buy the properties from this older investor in the future since his kids want nothing to do with them.

It could also present an opportunity to buy the properties from this older investor in the future since his kids want nothing to do with them.

For the most part they are nice and responsible kids.

The foundation is crawl space.

I had converted basement into a two bedroom with connected door to bath from master and living space with kitchen.