If you are planning to expand a Village in Minecraft or to build a base with a Villagers dedicated area, you certainly need to take care of the logistics. Other than making the village Zombies proof, a recurring problem seems to be Villagers that climb ladders and get stuck upstairs. So the question is: can Villagers climb Ladders?
Well, yes and no. Let’s see why.
Villagers can open all wooden doors. They can’t open trapdoors, iron doors and Fence Gates though (see also Can Villagers open Fence Gates?).
Technically they can climb Ladders, but their A.I. is designed in a way that makes them not consider ladders as a path. This means that they will not choose to use them, but they will if they get pushed into the block by other mobs (like other Villagers, for example) or the players.
They will also use Ladders if it’s their only way to get to their Bed, for example when their Bed is upstairs.
Once they’ll be upstairs, they will stay there, because they will not consider to descend the Ladders. If you need, you can always push them down. Once on the Ladders they will descend them immediately.
How to stop Villagers from getting stuck upstairs
If you want to prevent them from getting stuck on top, you can install a Wooden Trapdoor at the top end of the Ladder. They will not be able to open it.
To craft a Trapdoor you will need 6 Wooden Planks and place them in the Crafting Table this way:
Note: Wooden Trapdoors are also one of the items you can use to start crawling in Minecraft Java edition.
Another way you can prevent it is to break the first ladder block touching the ground. This way you will be able to use the ladder by jumping on it. The Villagers won’t be able to do it and they will stay at ground level.
This is the best video that you can find on Youtube on the subject. This topic doesn’t seem to be covered by many videos.