One issue that I had with a pair of boots while hiking the AT in North Carolina was that when I woke in the morning, I found that rodents (mice?) had chewed my laces. Presumably they were attracted by salt from tying the boots with sweaty hands (they also chewed the grips on my trecking poles). Anyway, since then I have always tied my boots or trail runners together and hung them across a clothesline that I run under the ridge of my tarp. I also hang my trekking poles.