Then buy the proper chemical to spray on that will take research to figure the proper type  .

Being from and raised in Texas I know a little about Arkansas and my daughter is in the 3rd year ar the University of Arkansas and is studying to be a chemical engineer.  

I've heard of nurses addicted to substances but have never met one (that I am aware of).Nurses are people like everyone else--some are good and some are bad.To address the main question, I'd venture to say that it's primarily dependent on the location and whether the area demands a lot of travel nurses or not.I am currently on assignment in Medford, OR and the hospital I worked for was heavily staffed by travel nurses, and temporary housing is scarce (housing in general is scarce) so accommodations are expensive--i was paying 1700/month for a 1bdr cottage, now paying 1200/month for a studio.That said, travel nurse pay rates are dropping all over, and if they continue to drop them there will be a decrease in demand for travel nurse housing.

At the time when the chemical industry discovered farmers as a huge market all sorts of herbicides and pesticides (the are banned today) were introduced, stored and disposed of basically into the ground: the farmer did not want to have stuff growing between the barn and the farmhouse anyway, so seemed like a good spot to kick that barrel over.

I found traps containing this substance on the rental side but I do not have a toxicity report from a vet (I was too distraught to ask for one).I removed the toxic traps, I do not trust my renter,  and I am uncomfortable living with a person who violated my request.

This powder kills fleas and is perfectly safe for humans, (unlike chemicals).

I started out as a sales rep for a concrete producer and I am now working for a chemical company as an area sales manager.

I started out as a sales rep for a concrete producer and I am now working for a chemical company as an area sales manager.

For example "No cooking grease, oil, animal meat bones, pasta, rice, any other substance down the garbage disposals except apple and carrot peels and liquids with no solid matter such as juice and soda" and "no vaping and smoking of any tobacco product, marijuana or any substance" on the property, including the backyard"  

That does not happen by accident, you must spec what you want.The wire shelves allow for easier painting on turns, (easy quick) visual conformation that the outgoing renter has not left (a handgun, illegal substances, or a big dead bug) up there.I am not aware of these ubiquitous shelves being a danger to life...Seems like the tail wants to wag the dog here--maybe a harbinger of things to come.Either the renter or you are the boss...maybe a harbinger of things to come.Good Luck!