I was noticing that crabs were extremely rare in my world even after disabling all other mods, so I tried to adjust the spawn rate with the config file. However, even ratcheting up the weight to 1000 doesn't seem to have any effect, and neither does changing the minimum group size. I'm using 1.16.5 and Forge 36.1.13.

Hello! Quark's moved to 1.18 now-- unfortunately, this means that (unless your bug is critical and/or game-breaking), we're closing support for issues filed for versions prior to it (e.g. Quark on 1.16).

If your issue still occurs on 1.18, or if your issue happens to be rather critical (e.g. consistently crashing the game with no other mods present), please leave another note or open a new issue. Thanks for your cooperation!