I hear a noise...what could it be?

There is something under my bed, or near enough to it to sound like it is under my bed. It is making some sort of banging, clicking noise.

Now, imagine a car taking a corner to fast. It skids around the lamppost, taking the turn on two wheels. Sorta Starsky and Hutch like....

The cat just did that exact thing.

She must have sonic hearing, because she wasn't anywhere to be seen. Out of the blue she came skidding into the bedroom, taking the corner around the foot post on two feet, glanced my way and darted haphazardly under the bed.
The other cat, her sister, is lying ON the bed and seems to be indifferent to the entire episode. She seems to be saying "TRYING TO SLEEP HERE PEOPLE! KEEP IT DOWN, WILL YA!"


Update:
Cat under bed...didn't find anything. But the noise has stopped. But she confidently came out with a smug look on her face. Wonder what kind of smack she was talking to the rodent? it must have worked. It has been silent since she walked away.