We used to shoot them at the local dump. The weapon of choice was the one we had. Since we were impoverished (or thought we were), we used what we had. In my case it was an ancient pump up pellet rifle. One of my buddies had a full auto (he wished) pump daisy. He could pull a Win M12 and hold the trigger back and pump. Lots of BBs flying, few hits. The pellet rifle was single shot, and you had to work to get 7 full pumps. But it was more accurate than me, so it didn't much matter. My range wasn't all that far, and I chose to only shoot the ones up close.
For a while the local PD hated it. I think what the one worthless cop hated was kids. He wasn't the chief, and the chief loved kids. The kids loved him back... go figure. We were given permission to walk out of town to the dump with our artillery. I had a tattered old note. When it finally melted, the chief gave us each a note saying he approved! My problem was pellets were ungodly expensive. A tin of them was just out of my price range, so I had to rely on charity, welfare, begging, you name it.
The dump operator hated rats. It was our salvation. He even supplied some pellets from time to time. When we got a little older and were allowed to use 22s, he furnished some of them, too. All he wanted to do was make sure we were shooting in a safe direction, and aiming. Once he saw how careful we were, he became our fast friend. No one else was allowed to pick the dump for goodies. We were. Particularly 2 cent pop bottles. He understood the money went to soft drinks and ammo. Even in the 1950s there were people who would rather throw away a deposit bottle than redeem it. I liked those kind.
When my dad finally agreed to let me use the terrible Marlin/Glenfield bolt gun, or lives changed. The neighbor gave me a scope for it. A 4x one, too. It had a 3/4" tube, part of which was frosted, but you could see the crosshairs, and it pretty much shot where it was aimed. Rats began dying at an ever farther range. I think they were smart, and didn't show themselves up close to where we were. The ones farther away could play at their leisure. Until we started thinning them. We used that rifle until we were maybe 18 and moved up to T-Bolt 22s. That set a new standard of accuracy, but the dump didn't want us to shoot there anymore. I think a business down the road complained.
We even contemplated finding some old food and making a bread crumb trail from the dump to their back dock!
The key we discovered is when you hike a few miles in the summer, carrying your gun, a canteen (can you imagine any kids today drinking water from anything but a bottle?), and your lunch in a knapsack, and when you left home you knew you only had 5 or 10 shots, you made each count. There even were days when the critters hid and we didn't shoot more than once or twice (actually, the term we used then was "twicet".) Limiting your shooting to certain shots, and not wasting it blasting away taught you to shoot. We were shocked a few times when rich kids showed up with a full brick of 22s and emptied it in an hour or two. We hit more with 10 shots than they did with 500. But they probably had more fun.
We had concluded they were rich because if they dropped a loaded shell on the ground, they wouldn't bother to pick it up, they just pulled another out of their pockets. Then they'd leave and we'd scarf up their leftovers from the ground. Worked out well for us. I think it kind of hurt my dad's feelings when we told him about it. He had more pride than I had. In retrospect, he had a better job than their fathers had, and our house was paid for, as was our car. Funny how that works.