My recommendation is to secure your coop. If a domestic cat can get in it then any wild predator can easily get in and kill the flock.
FYI calico is just a color and not a breed as Domino 7said. They are always female (rare exception if they have an extra chromosome) as well. I do love the calico's colors!

FYI calico is just a color and not a breed as Domino 7said. They are always female (rare exception if they have an extra chromosome) as well. I do love the calico's colors!