OK, so I don't lock all my chooks up every night.
In my main run, where we have two large coops, one broody coop, and one small isolation coop (this is for a broody and her young chicks before they get let loose with the grown ups, a way of introducing the little ones so the resident hens are used to them and don't bully them when they are let out) - we currently have 10 hens one brood of 3 youngsters that are now around 12 weeks old, one brood of 5 that are around 9 weeks old, a brood of two that are around 4 weeks old, and a another brood of two that have just hatched out.
This run is a very large area, about 50 metres by 30 metres, and has a 4 foot high fence with a single strand of electric fencing running along the top and another running along the bottom. It is a main unit so there is a good wack if anyone or anything touches it (it is not mains electricity, it is a small DC current, run off the mains) and gives a constant level of power as opposed to a battery operated unit that gets weaker over time.
This has been in place for two years and just once over that time have I lost any chickens, and that was on a really wet and windy night, when my llamas were sheltering in their shelter, oh yes, my llamas have access to the next field and guard the fence line on two sides, the two sides where predators, mainly foxes are likely to approach my land.
In this run, I do not go down and lock the chooks up, I leave the guarding to my llamas.
This year we decided to breed a few pure Light Sussex, I had 11 chicks hatch out and they are now around 12 weeks old, we think we have 7 pullets (females) and 4 cockerels which have been split up into two groups. The 7 pullets have had a refurbished coop, and a 6' high enclosure built around them, they too have llamas guarding one side, but as they are youngsters and not wise to the ways of the world they need shutting in at night, no electric fence up there as way too far away from any power.
The 4 cockerels are also in a coop away from all the others and only has a small fence but are closer to my office and have goats on two sides (not sure how effective they'd be against a fox, and in any event they are all locked up at night.
So, a new routine, these two sets of chooks need locking up at dusk, and whilst I have remembered most nights, I have forgotten once when a glass of wine seemed to ruin the memory, luckily nothing happened but I must not forget again, must I?