Magic Hspice extraction

Hey,

I was extracting a few circuits in magic to Hspice and noticed that
some spice files have a capacitance from Vdd to Gnd. I couldn't come up
with a reason for this capacitance. Could someone throw some light on
this?

Also, I'm thinking that when I extract, the capacitances generated
include the interconnect, gate and overlap capacitances? Am I correct?

Thanks!