Troubleshoot Fireflies Not Appearing

Check Your Location and Time

Fireflies only spawn in swamp and mangrove swamp biomes during nighttime. If you're in a different biome or it's daytime, you won't see them.

Verify the Data Pack is Active

Ensure the data pack is enabled in your world. Check your world settings or use /datapack list to confirm the Vanilla Fireflies pack is loaded. If it's not listed, the pack may not be properly installed in your world folder.

Check Spawn Rate Settings

If fireflies are sparse or completely absent, the spawn rate may be set very low. Run /function vanilla_fireflies:menu and increase the firefly count to a higher level.

Reload Chunks

If you recently changed settings, existing chunks may not reflect the update. Travel to new, unloaded areas or use /reload to refresh the data pack and force chunk regeneration.