I'm seeing messages in the master.log, I'd like to clean this up. Is this message normal?

[31/Mar/2014:02:25:02 +1100] child process 14699 exited with status 0
[31/Mar/2014:02:30:02 +1100] child process 15570 exited with status 0
[31/Mar/2014:02:35:02 +1100] child process 16455 exited with status 0
[31/Mar/2014:02:40:01 +1100] child process 17319 exited with status 0
[31/Mar/2014:02:45:01 +1100] child process 18174 exited with status 0
[31/Mar/2014:02:50:02 +1100] child process 19081 exited with status 0
[31/Mar/2014:02:55:01 +1100] child process 19971 exited with status 0
[31/Mar/2014:03:00:02 +1100] child process 20832 exited with status 0
[31/Mar/2014:03:05:01 +1100] child process 21733 exited with status 0
[31/Mar/2014:02:20:01 +1100] child process 13684 exited with status 0
[31/Mar/2014:02:25:02 +1100] child process 14699 exited with status 0

Thanks

"status 0" means the child process exited normally, so it's nothing to worry about