My hair gets these tiny knots in the ends. Why does it do that and how can I prevent it?

2 Answers

We call those "fairy knots" and typically they occur as a result of the curls winding around themselves and forming a knot. You can prevent it by tangle free techniques.  Do not go to bed with hair all over your head.  Do not roll your hair up in styles without combing it through.  Do your best keep your hair detangled and keep your ends trimmed. 
Add more moisture to your ends.