Sometimes having a hard drive on a non-level surface can cause clicking sounds. This is more likely to happen with older hard drives.
To see if this is the cause of your hard drive clicking noise, you should check the positioning of your hard drive. If your hard drive is inside of a personal computer (PC), you may need to take a panel off the PC case to be able to view the actual hard drive position. If the case is a tower then the panel to remove is normally a side panel, or if the case is a desktop then the panel to remove is normally the top panel. If the hard drive (or the PC case) is sitting on an angle, you should reposition it so that the hard drive is sitting level with the floor and see if that resolves your problem. Note that your computer should be shutdown before changing the hard drive’s position.