Whenever there's a centipede alive somewhere it spams the servers logs and console with:

[Server thread/INFO] [STDOUT/]: [com.github.alexthe666.alexsmobs.entity.EntityCentipedeHead:func_70071_h_:163]: 58.0 / 60.0

I assume from [STDOUT/] that this is very easy to fix, although I'm no Java expert. Maybe there is a config file where I can turn this off and I just overlooked it?

Edit:
Here's a log file that goes on for about three quarters of an hour
In those 42 minutes, the latest.log file grew to 30.158 lines, with the centipede outputs beginning at line 335. From that point on, the log consists mostly of these outputs, a few of them being generated every second.

update your mod.