It drives me a little nuts that they had not reinforced the fenceline long before all this, and that they have not been using polearms and the like. I mean seriously. Dig a damn trench, line it rebar spikes, and then occasionally torch the damn thing to get rid of the bodies. it is not that hard. For that matter, they obviously have some generators and power sources, a few rechargeable weed eaters with nylon blades could do wonders for some silent skull cracking. They could harvest a few solar panels to serve as the charging station. get creative!