I just bought a house in an old neighborhood built in the 1950s. It has roof rats. It took me $1000 to hire exterminator to rid of rats and seal all the entry points, mainly the worn out crawl space vents. However, I see rats running along fences, in my backyard, on neighbor's roof etc. It's disgusting. Then I found out that a lot of the neighbors have broken crawl space vents or just big cracks between their roof and the stucco joints where rats can access. I told a few of them about this and suggest that they should take action. But most of them just shrug off and say "they are only living the crawl space anyway.
I am a bit pissed
because their irresponsibility keeps the rat population high. They are not poor or anything. A 1300-sq-ft entry level house here starts at $900K. But somehow many people don't seem to freak about rats that much.
I guess most rats just live in attics or crawl space and eat the fruit in people's backyards. Maybe that's the reason why many residents here don't feel bothered.