How to find unlit points or fence leak points where mobs come from?

Question

I've surrounded a village with a 2-high fence and lit it up with torches, and all was hunky-dory until I heard a zombie trying to tear a door down.

It was just one and I dealt with him quickly, but there was a creeper somewhere in the area of the village too. I placed more torches, made the fence taller near "steps" where one could reach the top with a long jump, and... there was the zombie again the next night.

So, either I must have missed something (I fenced off quite a bit of area - I plan to make the village grow quite a bit) or there's some obscure spawning rule I don't know about. How to solve this?

Answer 1

Are all the roofs well lit too? The zombies could be spawning on them and then jump/fall off.

Another options is to install a mod that shows you the locations where mobs can spawn. For example: in Zombe's modpack there is a mod that does just that (all other mods in the pack can be disabled if you want). I've read somewhere that NEI(Not Enough Items) has an option to show the dark spots too.

Answer 2

Here's what I do. I go through and make a grid of torches. I generally seperate them with 5 squares. I think you can adjust them out a bit wider, but that's my preference.

For your fence, go throug, from both sides, and find where you can just jump to make it over the fence. Whereever you're able to make it with just a jump, and zombie can get through.

Answer 3

You may have witnessed a Zombie Siege, though a siege usually consists of several zombies.

Zombies can spawn in villages at nights, regardless of light levels or distance to the player. There is no known way to proof a village against a siege without breaking villagers' routines. You can always block all doors with a block of anything, trapping guys inside, or raise doors above ground, but the villagers won't be able to enter them either.

The most risky situation is when you are near the village, but not readily available to save the population - whenever you are within 128 meters of a village at night, they are in danger. Sleeping over nights can help, as the world is not simulated while you sleep, it just jumps to the morning for everyone. You also can not replace wooden doors with iron ones, as a house is a wooden door :)