Let's say I'm inspecting a room I want to rent and notice a distinctive smell and also a mousetrap. I say "Здесь мыши!" (There are mice here!) and walk away. I can't say "Вот мыши" (Here are mice) in this context.
On the other hand if I'm playing a game where I have to find mice in a picture and I finally find them, I say "Here are the mice!" (Вот мыши!) I can't say "There are mice here".