You can't really tell from the picture, but this is one of those big rat traps.
I'm still trying to catch Big Daddy. As Mary said, packrats are smart. They are really good at eating all the bait without tripping the trap, and when you really wedge the cheese in there, they just eat the exposed parts. Yesterday I sprinkled some sunflower seeds from the bird feeder around on top of the trap, thinking maybe they'd be more focused on getting every seed and forget to be careful. I don't know if that's what happened, but this is the first one I've caught.
Normally I'm a live-and-let-live kind of guy, but packrats are nasty. They mark their territory with a smelly musk, which I now have on one of the bags my snow tires are in. You often hear about them getting into vehicles and gnawing through wires and hoses, and I don't need that. I won't use poison, but the trapping is on. They may be bushy-tailed woodrats when they're outside, but in my garage, they're just plain old packrats.