Below is a website with interesting facts and comments about the Appalachian Trail. A couple of these items are provocative. For example, I don’t recommend thru-hiking the A.T. without a tent, at least in the spring and fall. This article says the 250 shelters along the trail can obviate the need for a tent, but what if a shelter is full and there is a rain storm or a snow storm? Early in the hiking season, shelters are always packed (see picture from my thru-hike) and many times I had to set up my tent in the general camp area of a shelter. In Maine, it got so cold in September, we set up tents inside the shelter if there was room! Tents are warmer.
I do agree that you will see a lot more mice than animals. And 90% of the mice will be in shelters. I believe most animals see you, but you don’t see them.
As odd as it sounds, I agree that a long steep downhill is harder on the knees than the up part. First, you are always in danger of falling going down if your legs are tired. Second, poles help but, poles helped me more when driving up hill.
Take a look at the rest of these interesting comments.