I just drag them out to create a new midi track also. Btw while I'm working I open up the chain view in the drumrack, select (shift + select) & group (command G) all the kicks, snares, closed hats, open hats, cymbals, toms etc. This seems to help my workflow by simplifying things visually. I usually eq each drum sub group and compress to the overall drum group. Then it's all set up to drag the sub groups or each individually out of the drumrack creating their own midi tracks, which you could also then freeze or flatten before export. I just started doing this recently, using the top side mixer type visual interface of Drumracks rather than the instrument window below. No biggie, just thought I'd mention it.
Basically extract chains, what he said:)