Humans are gross. Seriously. We have all sorts of weird habits that should really be done behind closed doors. Here's a list of some of 21 disgusting things that we secretly do when we think no one is watching. 

1. Nose picking in public

When Bob the Booger wants to come out, just make sure there aren't any cameras pointed at you.

2. Booger sampling

Even worse is if the camera catches you snacking on them.

The most famous booger eater:

Hello, Berlusconi!

3. Wiping said boogers on the wall and other places

Just because you have nowhere to flick that booger, doesn't mean you can make the closest wall its permanent home.

4. Wiping boogers on other people

Stop treating others as your own personal handkerchief.

5. Blowing snot without using tissues

Do you pick the floor or leave it to dry in your hands?

6. Nut pinching (for guys)

We are all familiar with the dreaded "nut itch". Just make it quick before anyone else notices.

7. Ear digging

Your ears are not where hidden treasures are kept.

8. Sniff it for ear shit de toilette

Ear shit has a distinct smell that some people just can't get enough of. But getting caught smelling your finger right after is just too much!

9. Butt scratching

Wedgies and digging deep into your A-hole are two VERY different things. If that annoying itch remains even after clenching your butt cheeks, just make it swift and make sure no one's watching.

10. Sniff it for anus de toilette

It's real. People do this. No comment.

11. Picking teeth in front of people

Just like coughing, we'd love it if you at least cover your mouth while doing this.

12. Armpit sniffing

I admit. I love the smell of my own armpit. Who doesn't?

13. Phlegm spitting

Doing this in public just screams "Low Class".

14. Phlegm / snot swallowing

Just because you can't spit, doesn't mean you can suck it back in!

15. Picking your dirty finger nails in public

Not only is this a sign of poor hygiene, it's also the quickest way to get your date to run in the opposite direction.

16. Sniffing toe jam

Some people really get a kick out of sniffing their own toe jam. We have no problem with that, as long as you do it indoors.

Here's an extremely gross video:

17. Taking creep shots

The next time you're sneaking a pic, beware! Other people could also be sneakily taking a pic of your own creepy-ass behavior.

18. Plucking extra-long nose hairs in public

Woe is the single strand that decides to separate from the rest of the stack. If this happens, just excuse yourself and remove the ticklish annoyance pronto!

19. Duck face selfies

Yes, this behavior is totally gross and overrated!

20. Exposed butt cracks

Only you are responsible for keeping that crack in check.

21. Wearing crocs

Spare your poor feet from the embarrassment being seen in public wearing Crocs.