I have had no problems with foxes for 9 years ( though we do have a lot around here) til last year, first, it beheaded my ducks ( they stayed out too late 

) so I put the chickens early in the coop,  then it came in the morning, so I let the chickens out later, then it came at midday and killed 2 of my chickens, it would have killed more, but by then I was outside screaming and yelling, even though I was outside, it managed to snag the 2. hen 

 all this happened over the course if a couple of months..the only solution was an electric fence, of course the flexinette was sold out ( obviously, i wasn’t the only chicken keeper with fox problems ) so I had to assemble the whole kit and caboodle 

 they told me ( I used electrified wires) maximum gap between the wires are 5 cm, anything bigger, the fox slips through !