Fog lights only when headlights are on?

I just noticed that the fog lights only work if the headlights are on. I have other cars that have fog lights. They will come on without the headlights being on. Whats the logic of this? Just curious.

 

Well, you can also use the fogs with just the running lights and DRLs (no headlights). Or you can do the fog-anytime mod if you want to run fogs and nothing else.

 

How do you do the fog anytime mod?

 

You should be able to search it.

I run mine with the DRLs though. Same thing without modding

 

I run my fog lights non time

WTF are fog lights? Seriously, do I have these?