Mostly we study big earthquakes because they are easy to record. So, we don't know how small earthquakes can get and if the same thing happens in big and small quakes. Fortuitiously, two earthquakes with magnitudes 3.5 and 3.4 occurred almost directly below a Berkeley Seismological Laboratory monitoring borehole in October 2003. More than 4,000 foreshocks and aftershocks to these events were recorded, thanks to their proximity to the borehole instruments; some of these micro-earthquakes had magnitudes as small as -2. This talk will explore what these tiny earthquakes can tell us about how the earth fractures.