Add a sample silhouette target with a nice, tight group in the head area.
So many ideas, so little time and money. NVGs, either handheld or on a weapon, are always handy. They're getting cheaper, too. If it weren't for the critters, trip flares would nice. Can you run some electric fencing to it? How about some old-fashioned rocks-in-cans noisemakers on a trip wire?
The vaseline on the post sounds like a good idea for a last-ditch defense.
ooh... electric fencing... you might be onto something there... :-)