Do they work? I've got mice in the garage and pack rats in the barn.

NO! they are meant to sell. I had an infestation of rats in my shop 2 years ago + I tried them with no results. My son knew a guy in the pest business that gave him something that we put in the attic + it got rid of them all, no smell either. It just dries them up. On a humorous side, I did lock one of my cats in the shop overnight + the next morning it looked like a war zone in there. I don't know if he caught anything but I can't have bottles of chemicals knocked off the shelves.

Yes they work, I tried the small ones in the house in one problem room and the problem went away.
The range of the units is limited so choose the right size for the job.
bb

For pack rats I suggest the glue pads. https://www.homedepot.com/p/Re...Hg-10096-6/100208417

It gave me satisfaction finding a tail and a foot one morning. Normally you would find the whole rat.

I gave up on snap-traps after watching a rat hit right across the neck, behind the head, by a snap-trap, turn his head sideways, pull out from under the bar, and walk away.

A friend has one in her garage. Works very well. It makes a high pitched squealing sound that would drive me crazy. I don't know if they all work that way.

I saw a video on Rat-X. I have used Rat-X before and saw no evidence it worked, so never tried it again. I may have formed an opinion too soon. Have a look. https://www.youtube.com/watch?v=jjo8ot9umQ8 The fact that I didn't SEE any "evidence" of its effectiveness may not have meant anything. I didn't go digging up their nests like this guy did.

I suspect a lot of the bad reviews were the same issues. They didn't SEE dead rats, so they didn't think it was working.

This guy's recommendation carries more weight since he has nothing to gain, one way or the other. He has a lot of videos on rat traps. He seems to be fascinated by the variation in traps available. He even raises rats.

If anyone knows rats, this guy does.

Thanks all, for your input.