That's a failure of code enforcement. I could have our local code guy on site in under 24 hours with complaints like yours. And if I could get lucky enough to actually snag a picture of a rodent, good god, all hell would break loose. Lots of things are just a ticket, but once their are rats, the real enforcement comes into play. That's what it took to get rid of a nuisance property down the street from us. They wouldn't do too much until we showed them a picture of a rat. In a matter of months they condemned the property and took it by force (the owner could not or would not fix the problem himself). Bulldozed it, sold the property to a new owner, and ta-da! It's now a nice, clean little house.