The wolves do it too and I have a group of them that spawn next to my cottage. I cannot do anything without having to fight 3-5 wolves every 5 minutes.
Not sure why this is such a problem that has always plagued isometric games in earlier versions especially in Alpha, but the fact that both animals and monsters can walk through fences, doors, walls and floors and when I can't is definitely a problem.
I have reproduced a way to continuously reproduce wolves. My plot is is right on top of a spawn point for wolves. I was trying to keep them out of my plot by building a fence, but the problems got worse. I went to get some wood, came back and there were 50 wolves that had spawned under my fence within a couple of minutes. I realized I could kill them, loot them and they respawn almost instantly.
I tried changing the layout of the fence to see if it improves or not and the problems is consistent if my fence sits on top of the spawn point. I even added a benches and craft tables, no different. It seems that the land spawns them because it doesn't recognize that they are there when a plot object is there as well.
