(Going for a creepypasta feel here)

Hey guys, I'm kind of making a throwaway account here since I don't really visit these sites much. I just had a question and wasn't really sure where I'd get a response without getting weird looks. So, here's my question.

Is it normal for someone to not have an aura? Or is it possible to obscure your aura from someone who can see them?

I guess i should elaborate a bit more on the background here. You see, I work at a nightclub. Yes, it the kind where blinds' gangsters and xerna fanatics have full on alcohol induced brawls. No, its not the kind with near-nude girls dancing on stages. Trust me, if it were I probably wouldn't have ever even observed this issue.
At this club its my job to do the odd jobs. You know, attend the gross mass-used toilets and fetch alcohol for the bars. It has me running around the place all the time and occasionally mingle with people. It doesn't exactly pay well but it gets the bills paid and sure as hell beats putting my life on the line fighting monsters. During my work, I end up seeing some weird shit too. I'm pretty sure I've seen some undiscovered viro's. Hell, there was once a domesticated minotaur trying to get in and I swear I once had to serve a bucket of champagne to a pack of goblins. although in retrospect those might have been just really ugly dwarves.

But I'm getting off track here. From time to time during my work I'll encounter void atronachs. Now I have nothing against void's okay? I'm completely fine with them, but these girls... Whenever i bump into them they just stare at me in silence. All four of them at the same time. They don't say a word but those fully black eyes basically force me to leave. It's no wonder most voids wear sunglasses to hide it. Makes them look like corrupted thralls. Now I've encountered these girls a few times. Sometimes they're getting drinks, which they never pay for. Not that its uncommon for handouts in clubs like these, but our boss is a real pennypusher so he wouldn't allow the bartenders themselves to pay for it and I doubt anyone would pay for those chicks. I don't care how sexually depraved you are, those girls are just plain scary.
Other times I've seen them go into the bathroom, or leaving them. It is always one or the other. I never see them enter/leave after. Almost as if there's a third way in through the bathroom. Pretty sure there isn't though. I would know since I clean them.

I never really dwelled on the thought of them though. They were just a fleeting thought, which was passed along by the urgency to keep working to make sure my boss wouldn't crack down on me. But a few weeks ago I finally got my grandma, an old priestess of Zerna, to teach me how to see auras. It takes a lot of time and meditation to get the hang of but it is really awesome to be able to do. If you know anyone who can do it, definitely have them teach you. Its worth the effort.

If anyone here can already see aura's, you know what its like. For those who don't, I'll elaborate. When you see aura's its like a second layer of vision. There's the common misconception that you switch it on and off, which couldn't be further from the truth. It is simply something you always do. Once you can do it, there's no stopping it. This aura sight makes going to the club a hundred times better. Whenever its midnight and the club is filled, it looks like a private laser show accompanied by music for only me to see.

But that's where the question comes from. Last night I encountered those girls again. But I didn't see an aura on them. At all. Not even a hint of it. It creeped me the hell out because from what my grandmother told me, everything that lives has an aura. Even most of the dead have an aura. So why not them? Is it possible to mask your aura? I've never heard of a spell that does that, and looking it up on the internet didn't get me any results.

Anyways, thanks for anyone bothering to answer this.