Well, my cat... hmmm.. she is moving all the time, even when she is sleeping,
so I have the best model for very quick sketches.
I love doing quick sketches because of high concentration they require in a short time.
I love ink because the line is always unexpected and different, I cannot control it completely.
I adore variations in lines that come up in those kinds of drawings.
There is also some expression in my drawings and paintings, so ink suits it very well.
Ink allows you to make mistakes, and some of them work great in overall. What I also love in this technique, because of letting yourself to make those mistakes, is the only thing that can drive you to make some progress and work even more.
Hope you like it :)