Deer Fence Penetration
Punching Holes in the Fence
Getting back to deer fence penetration (something that mainly afflicts polypropylene fences), the bucks with antlers generally are no problem. They usually aren’t around–typically being very reclusive and wary of both human habitations and unfamiliar territory. The problem is the does and fawns. They are not so wary (perhaps because they are less hunted), so they are much more likely to be near the fence, to lunge at it if frightened, or if they are seriously thwarted by a plastic fence to punch right through it with repeated blows from their noses They do this relatively rarely (they are much more likely to enlarge and ease through established holes made by small animals), but occasionally they take this more direct approach.
Fence Penetration from the Bottom
Many or even most failures happen because the fence was not properly installed. People (including many landscapers and other semi-professional installers) tend to be so concerned about getting the fence high (which is usually not essential) that they neglect its bottom.
The first instinct of browsing deer is to poke about the bottom of the fence. If the bottom just brushes the ground, even if it is staked down, the deer will poke at it with their noses and eventually work themselves underneath and through. This means that a fence set up this way is really vulnerable. To make it secure at the time of installation one needs to sacrifice 6 inches of height and to leave enough material at the bottom to create a “flap” of fence lying outward on the ground–in the direction from which the deer will come. This flap is then staked down securely every 6 feet, using an inexpensive foot-long ground stake, to create an effective barrier (see Installation: Securing the Deer Fence Bottom on the Grade Changes page).
What if you already have a fence in place and cannot easily lower it 6 inches? One answer is to get a strip of metal hexagrid fencing, which comes in strips 2, 3, and 4 feet wide, and position it along the bottom of the existing fence so that a metal mesh flap extends outward (toward the deer) a distance of 6 inches on the ground. If properly secured to the main fence and staked down, this will end penetration of the fence from the bottom.
The Deer–Small Animal Combo
This brings us to holes in plastic deer fences that are made by small animals. Ground hogs (woodchucks), rabbits, gophers, and various others with teeth capable of side-to-side scissors action (i.e., most small animals without canine teeth) can readily cut a hole in a polypropylene deer fence. Experience shows that over time a large share of polypropylene deer fences will be penetrated in this manner. It’s important that these holes be detected by periodic inspection of the fencing (see Deer Fence Maintenance) and that they be repaired–because otherwise they will be an open invitation for any deer that finds them to push through, enlarge them, and use them as a doorway through the fence. In fact, this is by far the most common way that polypropylene fencing is breached. Metal fences and polypropylene fences with metal skirts don’t have this problem.