I had some mice in the attic and they came down into a wall cavity. I
think I've got all of them but I'm not sure.

I was wanting to know if you should be able to hear mice moving around
in your attic (these are deer mice)?

On the day they came down into the wall cavity, I heard a lot of noise.
They were jumping around in the cavity, and I'm not sure what (if any)
sounds related to them walking across the ceiling to the hole in the
top of the wall.

Of course, now I cannot sleep and think that every sounds is a mouse.

The ceiling is a normal 8ft drywall ceiling with vapour barrier and
about 18" if blown insulation. I can see tunnels in the insulation, so
i don't know if they walk on top, in the middle, or on the drywall.

So, could some please tell me if there is one (or several) mice in the
attic, should you definately hear the sound of them walking, or do you
hear nothing, or do you have to strain to hear it.

Thanks in advance.