We've lived in our current location for more than a decade. About 1-2 years ago there was a serious uptick in rodent activity in our area.

We've dispatched probably a dozen or so, including a mega-rat male (probably 15" including the tail) that was sauntering around in broad daylight right outside our door. I couldn't safely get him with the air rifle with the background, etc.

A few months ago, I set up a motion activated game camera and was seeing them running around.

As others have said, there's more than one.

Tethering down traps is a good idea.

If they're inside, you could consider using the electronic pest deterrents that plug into the wall outlet. A relative has had good success with those.

There are also things like 'Rodent Sheriff' which is a mint spray, but they don't list rats as one of the effected animals.

$.02 worth,
Boss

Tearing them up.

Heck, I bait them out at the stables at home with some peanut butter.

You have to hunt on a new moon, or they will not come out.

I've checked a couple times today. No evidence of any activity. Maybe it's found a way in and out. Or maybe its up in the attic dead or dying. I'm going to leave all the stuff in place.

I just remembered a rat story when I was a cop.
Me and this other guy got dispatched to a local apartment building that housed the poor so you know it was not taken care of either..anyway, me and Brown get sent there for a disturbance call on the second floor.

Get there we go in and I get halfway down the hallway on the way to the last apartment and I get bumrushed by some 80 yo man running for his life, fear in his eyes, screaming....my partner, Brown, who is 5’11” 250 pounds of chiseled muscle (former marine) , starts to follow the old man and get the scoop.

I enter the apartment and don’t find anything..nothing, looking for some crackhead behind doors or in the sofa...nothing...Brown walks back in and says the old man beat him out of the building and was half a block away when he decided to comeback to see if I needed help.

I’m like yeah check the back rooms...we find nothing...Brown meets me in the kitchen and I’m about to open the cabinet doors when I see a tail going back into a five inch hole in the side of the cabinet....

I didn’t say a word to Brown and I position him in front of the cabinet...I took my (otherwise useless ASP baton) baton and tickle the tail while Brown can’t see me messing with the rat. About the same time Brown hears the rat-thinking it’s a crackhead under the sink, he jerks the door open.....a raccoon sized rat explodes out of the cabinet towards Brown who does exactly what the old man did and runs away..

I almost pissed myself laughing....it took me four or five minutes before I could call on the radio for Brown and I broadcast it like he had chased a suspect!! He wouldn’t reply on the radio and when I got downstairs he said “I hate you” and walked off....he didn’t talk to me for at least a week.

I did have the maintenance guy set traps for the old man.

Two glue traps have been moved several inches from where they were. None of the traps have been sprung. There is no food out there that's not in a trap. Still waiting.

Peanut butter and cheese are the traditional baits although I've my best success using freshly sliced apple pieces jammed into the traps.

I tried apricots and it was interesting but the apples worked, by far, the best.

I think this is what's happening:

I put a small have-a-heart trap in the garage baited with a piece of banana. Tonight I went out. In one of the glue traps next to the wall I found one of the poison bait cube. And evidence that something had been stuck in the glue trap and got out.

So now I have a rat eating poison and getting out of glue traps? Now he's fucking with me.

I have 8 glue traps, multiple rat traps that I spiked with brad nails, a have a heart trap, and poison strategically placed. All in a single car garage with an overhead open attic. And I still haven't gotten him.

You need one of those electric models shown on earlier videos. This guy needs to ride the lightning.

I had a rat zapper back in NH. Worked on 4 D-sized batteries. Worked like a charm. Critter goes in and steps on a metal plate to get the peanut butter and zzzzzzzst! Crispy critter.

I saw the battery operated rat zappers at Tractor Supply. I may pick up one, or a ten of them.

Thought we had a mouse
Regular mouse traps would be sprung in the mornings no mouse.

One day the smell started, it got awful about day three. I tore out the cabinets under the sink.
It was a rat and I about puked from the smell.
The thing was huge.

Early one morning I drove past an old service station and running away from the station was three rats covered in used motor oil. I don't know if they fell in the pit or were victims of an eradication scheme.

I used Rat Zappers a number of years ago, and they do work. Mine were outside, and the Az. sun did them in.

Hate to tell you this Micro but sounds like you have more than one rat there. Keep at it. You'll be successful sooner or later.