Often when dealing with groundhogs burrowing in a yard or under a foundation multiple holes can be observed. It can be frustrating and time consuming to set traps at all the holes simultaneously. With a little patience and planning identifying the holes to target can be simplified.
To alleviate the guess work and avoid a whack-a-mole situation start by covering every hole noted in the yard or foundation. You can backfill with loose soil or stuff newspaper in the holes. Observe the holes over the next 24hrs. Note which holes are cleared. Often times there will be an entrance and exit hole. In which case the placement of a live trap with a two way door system (open at both sides) can be fixed close to or directly in front of their burrow entrance/exit. This creates a funnel effect. This process can save a lot of time.
Groundhogs typically burrow multiple holes when creating their den. Some holes over time will become inactive. Avoid targeting those areas when removing ground hogs. Targeting their active sites gives the advantage to the homeowner.