What is that noise?
Incident: I hear a horse walking down a cobblestone street in the USA
Result: It's more likely a horse but it could be a zebra
Incident: I hear horse hooves in Africa
Result: It's more likely to be a zebra and unlikely to be a horse.
Incident: I see impression in the mud.
Result: It's an antelope/ deer (and it's unlikely to be a Bigfoot)
Now the issue of noise in the woods.
We hear noise in the woods. Whatever it is, it is certainly more likely to be non-bigfoot (and explainable) than Bigfoot making various noises. I'm not saying Bigfoot wouldn't make noises as it would make sense at some point it might need to (warning, mating, and so on). It is just this: the more likely thing becomes the more likely thing.