This is a question that I thought after reading Level 2, as it says that mice are present there. This implies that other animals could be found around the Backrooms. What do you think about it?
True because earth is decillions of light years away from the edge of our REAL universe (Not the observable one, don't say I'm wrong because of that, I still might be wrong though) and our universe is whatever this is 1.86e+12
Most likely animals would no-clip as usual, but most likely on accident, since animals won't even know what the actual fuck is going on once the no-clip starts. And then they enter to a new level, and think of what they have just done in animal minds, and act like regular animals again after that no-clip.