In Java Edition, cave spiders replace regular spiders when spawning in Sulfur Caves. However, on Bedrock Edition, this mechanic is absent, causing only regular spiders to spawn in this biome instead of cave spiders.
Steps to Reproduce:
1. Locate a Sulfur Cave in Bedrock Edition.
2. Observe the mob spawning in the cave.
3. Note the types of spiders that appear.
Observed Result:
Regular spiders spawn inside the Sulfur Cave, but no cave spiders are generated.
Expected Result:
Cave spiders should spawn in Sulfur Caves instead of regular spiders, matching the behavior seen in Java Edition.
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Can confirm in Preview 26.20.26
Included a more clear Steps to reproduce:
Steps to Reproduce
Open the world “No Cave Spider In Sulfur Cave”
Wait on the Lime Carpet for mobs to spawn
Once the command output ‘Mob: Here’ check which mobs spawned by flying towards the cave
Observe which mobs spawned
Once you checked, go back to the Lime Carpet and use the ‘Kill all mobs’ command to kill them, to reset the area
Expected result
Cave spiders spawn in the Sulfur Cave biome, just like Java Edition
Observed Results
The following mobs were observed:
Zombie
Zombie Villager
Skeleton
Creeper
Slime
Sulfur Cube
Enderman
Witch
Spider
Explanation
The behavior file of the Sulfur Cave has the ‘monster’ tag, allowing monsters (Skeletons, Zombies, Creepers, Spiders, etc.) to spawn. However Cave Spiders aren’t counted towards the monster tag, as they don’t have a file stating that.
Also, Cave Spiders don’t have a ‘cave_spider.json’ in the
behavior_packs/vanilla/spawn_rulesfolder. For a mob to spawn in a biome, they need to have a.jsonin the spawn_rules folder. So a file for that mob must be created to make them spawn in that biomePreviously, this file wasn’t necessary as these spiders only spawned from Monster Spawners in Mineshafts.