WD Elements 20tb clunking noise after few hours

I have a WD Elements 20tb external drive hooked up to my pc.

I don’t use the drive often, but after my computer has been on a few hours, the drive will suddenly make a clunking noise for a few seconds. It does not sound good.

It’s strange because I’m not doing anything to access the drive, but it does this randomly. What is this? Is this a sign that the drive is dying?