Some Critter is Digging Up My Flowerbed

I have evergreen bushes and Azaleas on one side of my entry path and Hostes and Tulips on the other side. Some critter is digging up only the side with the Tulips & Hostes. Other than stay out all night with night vision goggles & a M-16, can anyone give me any suggestions what I can do to stop this problem.

 

Is the hole rounded ? Or is it conical ? How big ? Any pics available. Once the animal can be determined, the proper bait can be used to catch it in a trap.

 

It not a single hole. In fact I couldn't see any hole. It appears to be as if something overturned the earth in a row the length of the flowerbed, approximately 15 feet in length by approximately 1 foot wide. It looks more "tilled" than dug.

 

In my area, this is caused by moles. They tunnel along just under the surface, creating the sort of disturbed line you describe.

As for controls, hmmm. Spent a year trapping them, they just got replaced by new moles from neighbour's yards. Trying to live with em now...