Factorio Forums

I vaguely remember seeing this as patched, but apparently not. Biters still sometimes generate worm only bases on expanding. Suggested fix: walk without rhythm as to not attract the worms.

I too have noticed and found this quite irksome on 2.0.77

134800 is still "Pending"

Gameboyaac wrote: Wed Jul 15, 2026 3:48 pm I vaguely remember seeing this as patched, but apparently not. Biters still sometimes generate worm only bases on expanding. Suggested fix: walk without rhythm as to not attract the worms.

Hello, thanks for the report,

Can you provide a save game?
Ideally one with the base and one before the expansion happened?

Klonan wrote: Wed Jul 15, 2026 6:20 pm

Gameboyaac wrote: Wed Jul 15, 2026 3:48 pm I vaguely remember seeing this as patched, but apparently not. Biters still sometimes generate worm only bases on expanding. Suggested fix: walk without rhythm as to not attract the worms.

Hello, thanks for the report,

Can you provide a save game?
Ideally one with the base and one before the expansion happened?

I can provide 2 saves, my most recent and one on the day it occurred, although the nest is already cleared unfortunately. I've marked where the base was in the attached screenshot:

Gameboyaac wrote: Fri Jul 17, 2026 4:05 pm I can provide 2 saves, my most recent and one on the day it occurred, although the nest is already cleared unfortunately. I've marked where the base was in the attached screenshot:

They still can be helpful, please upload them here and I can check them

Discovered worms only expansion in my game in version 2.1.12.
World was created in version 2.1.7 with default settings but I was playing on 2.1.12 when worms occured.
Worms spawned next to iron ore just outside southernmost wall.
There is 2.5h gap between those saves, I have no idea, when did worms spawn.

That's because the builder group happened to select only spitters.

Larger sized spitter can only build worms, meanwhile larger sized biters can only build spawners.

If the build group only contains biters, it would spawn only spawners without worms.

This is fixed for the next release, more info here:
134800