Why?

 Why do kids just stand in the doorway when you're trying to get in or just in your way in general? I've never understood this. 

I didn't do it when I was a kid and I don't remember my siblings doing it either but my girls? They are the WORST about doing this. 

We constantly has mosquitos in the house due to them holding up everyone from getting in because they just want to stop in the door frame. 

I just don't get it.