This has been a recurring problem ever since we replaced the composite roof w/metal. Have learned that a full grown rat can enter a hole the size of a quarter. Found a couple of entry points and fixed that. The weak point has been the ridge vent foam bird stop. When roof was first installed they missed a couple of sections, then had a couple of sections blow out in a 90 mph wind after that. This last go-around was caused by aging/shrinkage of same which has all been replaced now.
Only means of entry is removal of the soffit vents; tried glue boards first but that was a bad idea. If you didn't get to it immediately the rats would leave half their coat in the glue, never to be trapped again. Too hard to get traps in and service them, so went the poison route.
One episode we put a rat bait that the rat was supposed to get very thirsty, go to water and die.......yep, you guessed it......the bad news is they didn't, the good news is that the smell subsides in a few days.
This trip I uses some warfarin which dries them up before they smell. Seems to be working; first night sounded like a soccer game all night; figured we got him. Seems there was more, 2nd and 3rd night the same but nothing on fourth night and the few nights since, so I'm hopeful. Believe it or not, have not detected any odor this time.
Plan to put some more poison out in event we have another gain entry somehow.