Perhaps doing two layers, offset, so even if a determined creature reached through the first, they can't reach through both layers? (Like window pants that have a gap of air between them)
It fortunately doesn't seem like a super common happening, and I'm betting area has a lot to do with it. I...
I would recommend 1/4" hardware cloth, based purely on the recommendations of other quail keepers I've read on here.
I've read quite a few stories of rats and raccoons reaching through the 1/2" size to kill birds, and at least one person talked of rats that pulled bites of meat out, one clawful...