I am not sure what I have done in my Control Panel, but my Who's Online display now always shows under Guests:
    There are no anonymous users online.
and within the Search Spiders block, there are a number of unidentified users. I am pretty sure they are my "Guests".

Any ideas what I have done to achieve this? My "Search Engine Agents" list matches Gizmo's Spider List

BTW, Gizmo, I think it would help people if you added the path to the Search Engine Agents list to you Spiders List post:
    Control Panel > Display Options > General > Primary > Who's Online > Search Engine Agents
I always forget where the list is hiding.

I see what you are saying.
There is a line item for the spider but the spider name is blank.
I would suspect you have something hosed in the agents listing causing guests to appear as spiders but...

Maybe repost what you have here.

Another quick way to find the agent setting is.
As a admin when viewing the whos online.
You can select the I icon and view the agent listing for the unknowns.
That can help narrow down the settings to search for.

> Maybe repost what you have here.

Ha! That prompted me to find the problem. Thanks!

At the end of my list of Search Engine Agents list, the last line shows: WISEnut=ZyBorg
But THEN, there is a carriage return after that, so the actual last line is blank!

I just put the cursor in that last line, hit the backspace, then clicked the Update button. Checked Who's Online, and my guests are back!

Thanks for all the help.

Edit: As a software developer, I hate files where the end of the file is somewhere off on the far right of some long line. So I always end my text files with a new line. (Maybe Gizmo could also add something about no blank line in his Spider List post.)

I couldnt remember my password when I was viewing this on phone. Was gona say if you copied and pasted, more than likely there was a blank line that would cause this. Same thing happened to me years ago.

Gizmo, I see you added the path to the control panel location. Thanks!

Now if you could just add a reminder at the end to NOT allow a blank line, it would be perfect!

            Gizmo's spider list

I think that's more of a bug in the system that should be fixed...

I found a number of anonymous hits from
212.113.35.%, 213.186.... 119.%, 120.%, 122.% & 127.% all out of Ukraine

Checking the info icon next to the "Anonymous", it seems they were from AhrefsBot. So could I add Ahrefs=AhrefsBot to my Search Engine Agents list to put those into the Search Spiders area?

Maybe not worth adding to Gizmo's Spider List?

As long as the useragent matches that you're adding then yes... Test it and make sure it works and I'll add it in.

Ahrefs showed up again. I had this in my Search Engine Agents list:
Ahrefs=AhrefsBot

Under Who's Online, I get:
Ahrefs
213.186.119.141

Hovering over the "i" reports: Agent: Mozilla/5.0 (compatible; AhrefsBot/3.0; +http://ahrefs.com/robot/)