Why do girls do this?

Haha! Yes! I used to do that. It comes from a lot of insecurity and a desire to figure out what is going on in your head, This stops with time; especially after girls have driven their 1st boyfriends nuts and realized that it's an annoying turn off.

It's nothing negative. Guys and girls are just soooooo different. They're making comments because they're just trying to understand what goes on in a man's head. They want to understand you. Girls are naturally curious. It also sounds like maybe one or two of them may have a crush on you. That's all that is. It's harmless and nothing a funny quip can't fix. Hang in there!

It seems like a form of flirting to me. It's kind of like in elementary school when a girl punches you in the arm, it really means she likes you. It's hard to tell without more context but either way I think the real value here is that you can gain some valuable information from them.

Use their comments as constructive criticism. So if it seems like they are saying something negative about your behavior or actions, then you are getting good feedback. You can now use that feedback to make corrections in your life and make yourself more attractive.

They're just making fun of you because you're a loser. Hahahaha j/k that's not true (I just felt like doing that). I've had that happen before, girls are just like that. It means they're your friends and they're just messing around. It's a way of having a laugh, so do it back at them, it's called "bagging" so go bag back lol