Flooring of all types has the potential for squeaks. Floor framing dries and shrinks, and squeaks occur as fasteners become loose, allowing movement in the subfloor and framing. Hardwood floors are known for this quality as they dry during the winter.
For a quick fix, try sprinkling a little talcum powder between the offending hardwood boards. This may temporarily quiet the squeak as the talc lubricates the rubbing surfaces.
For a better quick fix, try Counter Snap. This screw fastening system secures loose hardwood floorboards and stops squeaks. You drive the slotted screw through a special bracket into the hardwood and subfloor. (For dense woods, you will need to drill a small pilot hole.) Once the screw tightens the loose board, you break off the screw just below the finished wood surface.
You will be left with a very small hole which you can patch with wood putty or colored filler – or just ignore.