Every time I leave the shelter, I make sure all doors are closed. However, from time to time I’m discovering wildlife inside.
Happened in 0.6 Samedi and in two July experimentals I tried.
They probably spawn inside, which does look strange I guess. Not to mention opening door to Mr. Brute MurderousBear while in critical condition might end your fun 
Haven’t had bear problems, but I agree that they shouldn’t spawn so close to a shelter.
Time to build some fences.
Dude… In post apocalyptic New England, worst and most dangerous monster you can ever meet is… Bear. While now he competes with Jabberwock, Brutus the Bear and his brothers still occupy first place, since Big red J is mostly settling in his new enviroment. Number of survivors who died to Bear menace is… greater than any number that zombies and rest of monsters ever managed to score. Moby has a song named The Violent Bear is away, I always remember Cata’s bears when I hear it
I heard about that, that’s why I think wildlife shouldn’t spawn within 5 or so squares from the shelter.
The real problem is the concept of a “sealed” environment like inside a building. It’s surprisingly difficult to dertermine whether it’s ok to spawn a creature inside a building or not, though I guess it’s reasonable to err on the side of assuming that building are sealed and not spawning animals inside them at all. (Just filed a bug to change this, so “bathroom bears” may soon be a thing of the past)
This gets more dificult though for fences, they won’t actually help since the ground “inside” the fence isn’t marked in any way within the game itself (building tiles get a “roof” flag, but terrain inside a fence wouldn’t) The best we could do then is a flood-fill heuristic every time a fence or wall or… anything blocking movement is either created or destroyed. This still has a problem in that the entire perimiter of the fence needs to be on the active map for it to work properly.
tl;dr it’s harder than it seems, will be making a basic change soon that covers most of the issues.
I suppose I could build a fence so that there’s no space between it and the wall?
Thanks for replying, Kevin.