twisting knots

Hannah has a horrible habit (wow, that was a lot of h's) of twisting huge knots into her hair. It is a completely subconscious thing that she does, mostly when she watches TV. Most of the time I can get the knots out fairly easily given a little time and patience, but twice now it has been so bad that I have had to cut the knot out of her hair. It is super frustrating. Thankfully, she's usually really good about sitting still and letting me get them out.