Ratting

Throw a pallet on the ground where you want them to hang out and put some of whatever they are eating under it.

Have you tried luring them with ground coffee? Try something that they have to sit and eat which they cannot run away with.

also try a red or green light.

I used a night vision scope (Pulsar N550) and a suppressed HW100 in .177 cal. Worked great ! I used bird seed . I would set it out for a day or so and then start shooting them once they felt at ease. That was the only good thing about living in the city at the time. 

Jamie

I shoot rats on a regular basis. The pallet idea is good because they do not like to be in the open. My rat ice cream is alpo dog food they love it. Have the pallet near their area but where you can bust them from afar. I know it's costly stuff but I use nitesite equipment for my ratting. Good luck with the rats it's very habit forming. PS: I sit on a chairgun table and shoot from the pickup bed so I'm out of the tall weeds around the grain silos I hunt. Stay cocked and locked they always pause for a second then it's helicopter tails when that lead hits between those eyes.