Entities related to structures, like Villagers, Armour Stands, Animals in animal pens, chest minecarts etc have been found to spawn again, when the chunks are unloaded and loaded again. This is independent of the fact if the said entities already exist or not.
For Example, if a village spawns with 5 villagers, if chunks are unloaded and reloaded again, the total count of villagers will become 10 the next time. Even if the villagers are killed, they respawn on reloading.
This has been tested for:
Villages - Villagers, Armour Stands, Animals in Animal Pens.
Pillager Outposts - Trapped entities like Iron Golems and Allays
Mineshafts - Chest Minecarts
To replicate:
In singleplayer, visit any village, take the count of villagers. Then disconnect from the world, and reconnect again, effectively reloading the chunks.
Expected Outcome: No change in the count of villagers
Real Outcome: The count of villagers would double.
This was not tested for all possible structures, but only for above mentioned.
Notably, it should also be tested for Bastions for piglins and brutes, Igloos for villager and zombie villager, End city and End Ships for Shulker and Elytras. I will update here if I'll be able to test for these structures later.
Entities related to structures, like Villagers, Armour Stands, Animals in animal pens, chest minecarts etc have been found to spawn again, when the chunks are unloaded and loaded again. This is independent of the fact if the said entities already exist or not.
For Example, if a village spawns with 5 villagers, if chunks are unloaded and reloaded again, the total count of villagers will become 10 the next time. Even if the villagers are killed, they respawn on reloading.
This has been tested for:
Villages - Villagers, Armour Stands, Animals in Animal Pens.
Pillager Outposts - Trapped entities like Iron Golems and Allays
Mineshafts - Chest Minecarts
To replicate:
In singleplayer, visit any village, take the count of villagers. Then disconnect from the world, and reconnect again, effectively reloading the chunks.
Expected Outcome: No change in the count of villagers
Real Outcome: The count of villagers would double.
This was not tested for all possible structures, but only for above mentioned.
Notably, it should also be tested for Bastions for piglins and brutes, Igloos for villager and zombie villager, End city and End Ships for Shulker and Elytras. I will update here if I'll be able to test for these structures later.