seldom
It be the first scent they come to.
IMO, too close, inches! When they're that close to both and they're more interested in digging the trap rather than the scent that's been applied? Nope, don't buy into that philosophy unless you've been so careless that you've rubbed lure or bait on the trap to such a degree that the animal finds the trap more interesting than the lured set!!! . Never have! That's why I don't believe contaminated traps to be the cause for digging in most cases. Coon, skunk, and squirrel love to dig in fresh turned dirt and can hook a trap and uncover it.. A canine stepping on a poorly bedded trap jaw or lever will make that animal wonder [Please excuse my language... I'm an idiot] is in the dirt and can cause scratching.
The few times I've had this happen over a lot of years canine trapping was due to me poorly bedding the trap. I saved a lot of time and energy by just adding a 2nd trap and ending that particular nosey canine's desire to scratch further the next time through. I know it seems part of human nature to THINK we did something wrong and first and foremost we ASSUME we've somehow contaminated our traps rather than look at the set itself! Thinking of the "here & now" of the set construction first is far better and far more efficent than pulling all the supposedly contaminated traps, reboiling them, rewaxing, and resetting!!!
Just my opinion based on my own experiences!