One big benefit to using snap traps inside bait stations is that the rodent cannot move or drag off the trap after it has been triggered. This method also allows you to use attractants behind the snap trap, pushing the rodent’s head through the trigger. This creates force flow for higher kill rates. This method gives the full benefit of the force of the spring connection to the rodent’s head with no recoil.
from Pest Management Professional http://www.mypmp.net/2018/09/04/use-snap-traps-inside-bait-stations/