Escaping under chicken wire-

I surrounded my coop/yard with nice size rocks in the front and logs on the side and back - yes both inside and out.  Works like a charm.  Also deters any animal on the outside from trying to dig its way in.

If you want it to look nice, you can even get the large decorative rocks frmo somewhere like Lowe's or Home Depot.

or run a 6 inch board from post to post. nail the chicken wire to it. They wont be able to push thru it.

my fence was burried a couple inches under neath the ground, but they decided to make a dust bathing hole there so now anything can get in + out.

On the neighbor's coop, I took 2' chicken wire and placed it on the ground, perpendicular to the fence. Then we took the thin wire which the manufacturer wraps around the roll and used it to stitch the 2' wire to the wire on the fence. That was covered at the edge where the fence wire meets the ground wire with a row of bricks.

Our idea here was that a predator who walked up to the fence and wanted to dig under would try to dig down - not realizing they had to move a couple feet back and tunnel under.

we buried our fence 12 inches and poured concrete in there...then covered it with dirt again..  seems to work great.  they quit burrowing underneath..

I also  buried my wire  about 2 ft out with dirt......no problems since.............

I've got old railroad ties (or at least boards about the same size) around the insider perimeter of my run.

I like the cement idea!  Keep in mind, to make it even eaiser, you can just pour a layer of redi-mix onto the fence and burry it. Rain will turn it into cement soon enough, you do not need to take the time to mix it and dump it in.

Thanks for that idea, this will come into play when I build my coop!