multiple pie-charts on one figure

I am attempting to use subplot with pie charts to get multiple pie
charts on one figure.
I modified the as show below. Unfortunatly
it seems that the second pie-chart is written on top of the first.

How do I get multiple pie-charts on one figure? Is subplot the wrong
way to do this?

         from pylab import *
         # make a square figure and axes
         figure(1, figsize=(8,4))
         ax = axes([0.1, 0.1, 0.8, 0.8])

         labels = 'Frogs', 'Hogs', 'Dogs', 'Logs'
         fracs = [15,30,45, 10]
         pie(fracs, labels=labels)

         labels = 'Frogs', 'Hogs', 'Cat', 'Cans'
         fracs = [15,30,45, 77]
         pie(fracs, labels=labels)