Welcome. Thank you for the pictures. Your chickens are very pretty. Your runs are not secure. They need to be covered, top, sides and with an apron - with 1/2 inch hardware cloth. An apron is when you run the hardware cloth to the ground and fasten and then run it on the ground about 2-feet around the perimeter. This prevents digging predators. You definitely have weasels in your part of the country and then can get through anything but 1/2 inch hardware cloth.