I live in the country and have lost 4 hens last year, 4 this. Last years attack was at 1.10 pm, the hens were in the field, we were out in the garden having lunch, I will never forget that noise, we lost 4 in one go!
This year, all attacks have taken place around midday, and one day I saw a fox sitting next to the pen at 12.30 when I returned home. I am sure this is not a freed urban fox as I cannot think that the french would do that.
The losses led to my rooster becoming extremely over protective and he would attack us whenever we got within 10 metres of his girls.... He went in the pot, and my girls now stay in their pen - which will be extended next year with electric poultry netting.