If the infestation is not as bad, the boric acid should do the trick.

The exterminator might have solved the problem, and the tenant then subsequently brought in the new infestation.

Work with an agent until your an expert.Certainly entitle to your opinion, however, mine would be to say that if you didn't know how to make an offer on an investment property without your agent, perhaps you should have become more educated first before jumping into shark infested waters.

The biggest thing I've ran into was a serious roach infestation.

....but.......without a doubt, our worst tenant ever was a military guy, we suspected he was in dog fighting, and brought roaches, and then never told us about the roaches, so when he moved out, it was a crazy roach infestation,  and then he just left all he stuff/trash outside.   

Our team is available 24 hours a day; this allows us to work to prevent problems such as mold or infestations that might reduce the value of your rental income property.

Ummm, off the top of my head....back taxes, liens on the property, asbestos, termite infestation, a former drug house or a murder at the location, crap neighborhood that no decent person will want to live in.

I found out that the upper cabinet was ready to fall off, the microwave handle was melted and broke off, there was an ant infestation and a rodent infestation, the backdoor has been broken down once which was simply glued back together and used again, the bathroom was moldy and grout falling out which created more mold, and I didn’t find this last one out until after I left but every single fire detector was broken, which is serious because being a firefighter too many people have died from such a useful device that is required by law.

My homeowners insurance covers mold infestation up to $4000 and has a thousand dollar deductible.

Think hoarders with food lying around and resulting large scale roach infestation.