I was trying to see which one of my hard drives was making clicking noises so I unplugged one to listen to the other. When I plugged one back in and turned on my computer, it said that both hard drives were "degraded." (I'm using RAID 1.) I'm guessing this is because I unplugged them? (I unplugged one at a time. So at any one moment, only one drive was plugged in, and I did it to both drives.) I'm guessing this means there isn't an exact copy of the information on each drive now? How do I fix this? I don't have any important files on here so it's not too much of a problem, but I'm not sure what to do. Thanks. (One more question. Should the hard drive be making slight clicking noises when it does a lot of reading/writing? They aren't loud, but noticeable up close. Thanks.)
What would have happened is when you unplugged the first drive, it simulated it dieing and disk IO continued but only making new data available on the one drive, when you did the second drive it probably got a little confused and you may have lost "some data" although I doubt you were modifying any files or doing anything that would be a "huge" deal at the time. To fix it you will need to figure out which drive it thinks is most "up to date" and then rebuild the array onto the other drive, depending on your controller this may or may not be too bad a thing to accomplish.
As far as the clicking sounds, it may be an indication of upcoming failure and you will want to have either replaced the drive, or at least made and effort to have a new drive on standby.