As much as I hate to drag up a comment from nearly the beginning of a thread...
So what you're saying is that your rental will never have a mouse/rodent problem.
How exactly would a person looking at your house know there are are 15-20 cats living the house next door?
Going out on a limb here - and I don't mean to be curt - but I'm guessing you haven't lived in a neighbourhood with a crazy cat person. If there are close to 20 cats living in the house next door,
you'll know. Trust me. Cats don't tend to stay indoors. If you have a house in your neighbourhood where there
are 20 cats all living indoors, then congrats. However, they generally don't. Where I used to live, there was a slightly unusual old lady who kept a high number of cats who she could barely keep control of. Yes, the stereotypical crazy cat lady. When I say she couldn't keep control of them, I don't mean that these cats were particularly unruly or anything like that, they were just regular(ish) cats who didn't really respond to being spoken to.
The problem she caused was that these cats would often lounge around her house or the general area.
She'd leave food outdoors for them. This food obviously attracts rodents and the like. I don't really recall whether the cats were well looked-after, but you could certainly smell them (and the turds) as you walked past. The kids who played outside generally avoided that house (I was one of them). It's a generally unattractive look.
Saying all this, I mean no disrespect to Yttrium, or to people who own cats - especially those who do so responsibly.