fox in the hen house

ok it wasn't in the hen house but yesterday a scraggly old fox ran through the yard. he raised quite the hub bub with the girls!! luckily i caught a glimpse of him out of the corner of my eye and i went to investigate. there he/she was between me and the coop. i yelled for josh (apparently he didn't hear me because he never came) then i start yelling at the fox along with all the hens that happened to be right there. darn thing ran off into the woods, but it makes me nervous to think it's around. i check on the girls alot more often! makes me wonder if the chicken tractors are safe ?!?