Beat me to it - not a good enough job on keeping your hens safe!
I thought my duck run was secure - 7 foot netting, latch on the gate, heavy wooden drop down pophole - my dog opened the latch, lifted the pophole with one paw, reached in and retrieved a duck - brought it to hand very pleased with himself,

so I couldn't rage him - but a fox wouldn't have been so obedient and just as clever in opening things. So it's a deadbolt on the gate today, and a snib on the pop-hole. Makes life more complicated for me, but the ducks will be safer.