I live next to a macadamia nut orchard, so rats are a given. I have farm dogs, but none are terrier types, so they have no interest in the rats. I keep cats, which have been successful in keeping the rats out of the house. But I still have plenty of rats getting into the sheds, the gardens, etc.
I don't use prison because I have dogs and cats, plus we have an endangered hawk that visits our farm regularly. So I've used snap traps off and on. I say off and on because the rats seem to get wise to them. I'll catch a bunch of rats, then nothing for weeks or months if I simply let the traps stay there. So I'll use the snap traps until kill numbers fall off, remove the traps for a month, then repeat. I get primarily young rats.
The best rat trap where the rats don't seem to learn about avoiding them are the electric zapper type. They run off of batteries. I have one that I keep in my
solar electrical shed in order to protect the equipment. (By the way, rat proofing anything here is almost impossible unless it's a
concrete bunker.) it's not uncommon for me to get a rat every night in arow. For some reason the rats don't learn to avoid it. I'm right now thinking about buying three more for the greenhouses, if they go on sale. They are expensive.
I have a few of those trashcan/water/seesaw rat catchers in the garden area. I catch
enough rats in them to keep down the damage to my crops to a bearable amount. But many rats eat the veggies before they find the water traps. So I've had damage to pumpkins, squash, cucumbers, tomatoes, lilikoi, potatoes, macnuts, etc. I've lost large sections of freshly planted carrots and beets to rats.
Dead rats are useable for fertilizer......I bury them in the garden rows. Or as chicken food ......they go into the feed cook pot whole as is. The chickens love them cooked.