Rats

While this doesn't answer your question, you would find that cats are great in controlling rats.

It depends on how much food is around. No food, no rats.

Sorry, I assumed that the rats would leave the building to hunt, and use the building to breed and for shelter only. I have a thing about rats, and the thought of rats makes me want to live in the Australian Outback, where rats should be rare owing to lack of food!!! Hell they bug me. Thanks for your help. Is there any good thing about rats?

If you're thinking about moving to Aussie-land to try to avoid rats, think again. They certainly have a rat population propagation issue there as well.

I read somewhere that rats at least eat cockroaches. The big ones I mean. And they eat mice.

BTW, a neat fact about rats I just learned right now:

Next to crows' murder of crows that's by far the greatest term for a given herd of animals in the English language.
http://wanttoknowit.com/what-do-rats-eat/

White lab-raised rats have plenty of good in them. However, you are clearly not talking about them so I'll not go into how useful and their various virtues.

Unlike rats, cockroaches have never implicated as a vector of any disease. Needless to say, roaches are less cuddly than rats.

I never said my fear of cockroaches was rational. Cockroaches are evil. I've seen many rats underground by or on the subway platform. They don't bother me there. I just might change my mind if I actually see one in my house.

I suppose I wouldn't want to cuddle EITHER wild rat or cockroach (wild or domestic). I maybe would give a hug to a domesticated rat.

Interesting factoid: I was curious whether or not cockroaches carried a health threat to humans:

" ... Cockroaches leave chemical trails in their feces, as well as emitting airborne pheromones for swarming and mating. These chemical trails transmit bacteria onto surfaces."
- - -
"Cockroaches are one of the most commonly noted household pest insects. They feed on human and pet food, and can leave an offensive odor. They can also passively transport microbes on their body surfaces including those that are potentially dangerous to humans, particularly in environments such as hospitals. Cockroaches have been shown to be linked with allergic reactions in humans. One of the proteins that triggers allergic reactions has been identified as tropomyosin. These allergens have also been found to be linked with asthma."

Umm. Maybe I've just been repeating urban legend. I might be tempted to research this after lunch.

Rats and Mice tend to live somewhere near their food sources, although they will also seek out safe places to live/sleep/breed. But they don't like to travel far between food sources and home, so if you keep food away it helps deter them from living there.

Mouse and Rat populations tend to expand to fill an available area until they consume all the resources or are controlled by predators. As such, the idea of killing all the mice in a building before you have closed off their access points only serves to create a "vacuum" whereby more mice will be drawn in (from the available population outside). And keeping Mice and Rats out of a large building can be completely problematic.

Since you can't really make a vacant building any less inviting to a Rat/Mouse that wants a home, about the only thing you can do is to make sure there is no food around (and that especially includes outside the building, like dumpsters and stuff).

Subway Rats Spar for Trash and Glory
http://nymag.com/daily/intelligencer/2015/01/video-subway-rats-spar-for-trash-and-glory.html?om_rid=AAApgi&om_mid=_BUvrhxB8$4uwS$