Why do you use hardware cloth on the run?

[Azriel]

Is it just to keep coons from reaching in? I would think if it only goes up 3' weasels and ferrets woud just climb over. If there are screens on the coop windows, and the chickens are not near the windows, do you still use hardware cloth or is 2"x3" heavy welded wire OK.

 

[Mamahalo]

3 feet is all?

If you do not fear Hawks and have elected not to have a "roof" on your run then hardware cloth is only really neccesary for the run perimeter to keep daytime prowlers at bay. I'd put hardware cloth just a few feet up around the base and 2 feet flat out buried on the ground to keep coons and dogs and such from digging under or ripping weak wire apart and reaching in through welded fencing to snatch. Higher than a few feet the hens on the ground aren't really in danger of errant paws, but remember, ferrets aside, racoons and cats can climb too...
And hens can fly up pretty high if they want to get out.

If you don't have daytime predators then chicken wire will keep the hens penned... no need for hardware cloth as long as the coop is secure.

my opinion

 

[Ole rooster]

A lot of folks don't range their chickens. So that means they are in the run all day. When a chicken get spooked or frightened they tend to crowd into one spot and that is always against a fence or most times in a corner. If they are at ground level even in a pack, varmit cannot get their paw through the cloth. Now if you have a perch in the run and they are above the fence all bets are off. That is unless you have run the HC up to where they would be against the fence on the perch. It is very good insurance but somewhat expensive, but worth the cost.