You can probably do night vision monitoring with your current camera using little additional hardware. Most CCDs are actually quite sensitive to IR light, which is invisible to both human and mouse eyes. The only thing to watch out for is that some cameras have a physical IR filter over the lens (which can usually be removed with little fuss).
Wire up a few IR LEDs or even an IR spotlight and the camera should pick up the full scene, day or night. It would be interesting to see how well mvc works in such a setup.