How to mice/rat proof the coop floor?

[aumismommy]

I'm new so bare with me. We just re-homed our last flock (all turned out to be roosters, not so good luck I guess) and will be transferring our new babies out to the coop in a couple weeks. While we were just cleaning out the coop we noticed many burrow holes in the coop floor (dirt on the bottom floor, then there's an upper level that closes off from the rest of the run that is wood and we put shavings up there) that go right under the coop walls... as in from the outside under the wood then into the coop.

I've heard and read that the best way to prevent this from happening is to bury hardware cloth in a perimeter around the coop - like 12 inches deep. So my first thought is ouch that's gonna be expensive but oh well if we need to do it, the second thought is - is it just the perimeter that needs the hardware cloth...not the floor? Do the mice just not dig any deeper than that and then give up? Should we be doing a flooring instead... and if so what kind? Plywood, linoleum? I've seen all types... Help me please?

 

[ll]

A skirt of hardware cloth will not prevent tunneling mice/rats from getting in to the food.
The perimeter skirt is to discourage digging, like from dogs.

We enclosed our entire run including the bottom with hardware cloth.
The hardware cloth in our run is set deep and we put dirt & fallen leaves & grass clippings on top.
Rodents can get into very tiny holes, doing the floor in chicken wire won't work.
I have photos on my Hen House link ~ good luck!

Edit: Post of photo of your set-up when you can for additional advice.
If you do put down linoleum/plywood/etc. still use hardware cloth as an in-between layer because rats can chew thru wood & plastic easily.