i have these wierd little 'things' protuding out of my skin. it's hard to explain so you can get a visual, but they're small, you can't really see them but u can feel them when you brush your hand over the skin. they're hard and the size of a pore basically. mostly they're on my hips, thighs and butt. they're not blackheads, because blackheads are kind of mushy and have to be squeezed out but these things you can literally pull them out or pick at them until they come out-they usually leave dark red marks behind. these things kind of look like blackheads (only rock hard) because they're white with a black tip, but sometimes just white. what are they, what causes them, and how do i get rid of them?