This is a sad reality, and problems will only increase during the Mi. winter when birds are likely confined to the coop.Key point.
30 chickens should have a minimum of 120 square feet in the coop -- 10x12.
While *theoretically* a large flock in a large coop *might* be able to tolerate higher densities because an individual bird has more space to avoid another individual bird, 8x8 is only a little more than half the suggested space per bird.
2 square feet per bird is commercial density -- where behavior problems are "handled" by debeaking the birds so they can't kill each other and intensive breeding selection for birds that can handle the conditions (see hatchery catalogs where certain breeds have a note "tolerates confinement").