I see really nice people posting on forums about how their hens are missing then see them comment that they:

*Only turned their backs for a minute or two or five
*Went inside the house to make a cuppa
*Left the hens free ranging because nothing ever happens
*Don't bother with fox deterrents because it's expensive
*Don't think there are foxes in their area
*Know that there are foxes in their area but don't think they visit their garden

I really feel sorry for each and every person affected by losing hens to foxes because at their very hearts they DO care for their hens but at the same time have somehow minimised the fox risk in their minds.

Foxes are a real threat. They are pervasive, they are everywhere and they want to kill your hens. Think of it as their goal in life. They aren't evil, it's just their nature. The fact that it's at odds with a chicken keepers goal is just a fact of life.

They may not even be hungry but they will still target your hens because your hens are there. They kill for food primarily but they can't help attacking chickens as they are easy targets generally and also very instinctive targets satisfying all of their basic needs as a predator. Flapping and squawking excites them and incites a bloodlust that explains massacres above and beyond a food need, but you can help prevent an attack.

If disturbed and if they feel threatened enough they sometimes lose the chickens from their grasp and flee.

Posting this, I realise that even though we take great measures to protect our hens, we might still one day be fox victims therefore I'm very cautious about sounding preachy.

I have gathered some advice together to post to minimise the risk to your hens. However you cannot wholly eradicate the risk due to human action, inaction or simply fate.

1: Ensure your run is fox proof. This is partly done by using wire meld mesh and not chicken wire. Foxes can easily chew through chicken wire because it's so weak. Ensure the weld mesh is 1/2 inch by 1 inch to ensure rodents have a hard time getting through and 16g thick if possible.

2: Ensure the run cannot be dug into. The eglu runs have a few inches of external mesh to lie on the ground forming a perimeter so that foxes try to dig into the mesh, which they can't. If you don't have an Eglu run, ensure that your run has paving slabs surrounding it so they cannot dig into it. We have slabs around ours and also our run floor is slabs so they can't dig upwards into it.

3: Wood. If your run is constructed of this, ensure the width of the wood is large enough so the foxes can't chew through it. Remember, they have all night to proceed with their plan! Two inches thick (2"x2") should suffice but is no way a guarantee.

4a: Construction of run and the components notwithstanding, you should also have some form of fox deterrent. Fox-watch, human male urine around the perimeter, human male hairs in porous bags around the perimeter, these all combine to deter foxes from your area however they will never prevent them.
http://www.conceptresearch.co.uk/fox.htm

4b: If a fox has visited your garden, you can bet he'll be back. Your garden is now on the shopping list and will be inspected regularly for weaknesses. Deterrents will help lower the frequency of visits, that is all.

4c: Electric fencing, if used, can be a good deterrent. However it is only good if switched on permanently. If a fox tries a fence and it's not electrified just once, the area is back on the shopping list.

5: Vigilance. NEVER EVER leave your hens free ranging unattended for a second. They will eventually be killed or you may think they are just missing. It doesn't matter for how long, or for what reason. The fox only sees a hen and an opportunity. Sometimes you see evidence of a fox attack, sometimes you just have an empty run.

6. Locking. Fit good quality clasps, bolts and padlocks to your run enclosing your eglu or coop. This will not only prevent foxes but will hopefully deter aggressive human intervention. It's not unheard of for vandals to let hens free and put them at risk to foxes, or commit acts of violence against your hens.

7. Missing hens. Hens will go into fight or flight mode as every creature does under threat, even humans! If your hens see a fox attacking a member of their flock they will seek safety or fight. Chances are the former.

If a hen has decided to hide, they will be hiding from everything as their home has now become unsafe. Do not be surprised if after an attack you cannot find surviving hens, they are terrified and will try to remain hidden. Worst case is that they don't survive, generally they are wounded, sometimes mortally. Occasionally you get to hear of happy stories of reuniting, these are rare.

It's up to you now to try to reassure them the area is safe and the best way to do this is to call them using your usual methods as they will be used to these. Additional methods that they are not used to COULD serve to make them more scared so be careful. Try not to let your feelings of panic enter your voice, be as calm and normal as possible. Search surrounding areas, neighbouring fields and gardens, being as gentle and as observant as you can. Inform neighbours to be watchful.

However, overall the best outlook is to prevent this from ever happening and to ensure your run is safe and to never, ever leave your hens unattended.

Many will disagree I suppose and read this saying that they have let hens free range and never had a problem. Well you are lucky, many others aren't quite so lucky. And each hen keeper does things their own way as is their right.

With all the best will in the world, we will try to ensure the safety of our hens and achieve an acceptable balance of quality of life vs lifespan. This is something you may agonise over as well. However we realise that one day, we might lose a hen or two to Mr Fox.