set some rat trap and put a camera to watch it.
Please, no hate emails but lately I found some Youtube videos of guys mostly hunting rats with high powered air guns with scopes. Sick but interesting when you see these guys take out a ton in an outing…
snap trap are consider humane. most of the time they die pretty fast, occasion they do suffer if snap in wrong location, but overall better than a lot of other trap. maybe zapper ones, i heard those are pretty good too
Who cares if the traps are inhumane? These are pests.
About 40 tears ago I worked for a restaurant chain in Chicago. We had one restaurant that was located in the downtown area. They had an unusual method for controlling rats. The pest control guy put down very sticky tape in the store room and the rats would get stuck on it. Every morning he would come in with a hammer and kill them and throw them in the trash. He never got them all but the problem got a lot better.
Ultrasound can be used to drive rats away from your house. I’m not sure whether your neighbor will be happy about this humane method 
I don’t think you want to drive them away, you want to kill them. Other than food for Owls, which we don’t have in urban areas, they contribute nothing to the food chain or the environment.
Rats also have life, emotions and friends. Is killing too inhumane to rats?
You could have this argument about anything down the food chain. How about ants? How about bacteria and viruses? They kill more humans than anything else.
Ultrasonics don’t work - they just learn to dance to the music or so I’ve been told by people with warehouses full of feed and grain.
“Public housing” says it all. They’ll never be gone for good if people leave crap everywhere. Solution is the same as for homeless - stop feeding them and they’ll go away.
I’ve lived half my life the exurbs and never had rodents from outside bother me inside. If you don’t want rats don’t be a pig.
Please stop eating - you are killing all species.
Eat plants 
Invent an energy bar that is not derived from any living things is the ultimate.
I subscribe to sheriff’s view. Has to be part of the ecosystem that help sustain/ balance it. If it is destroying the ecosystem - kill them
But I can’t kill myself by not eating. I’m only interested in animal rights when it’s convenient to me
Everyone is so human centric here
JUST EAT RATS
Old school Chinese put mice in wine.
Eat vegans
my family had one of those in hk when i was a kid.
Did you drink it? It’s supposed to cure some diseases or shit like that.