WD Red WD3001FFSX - 5 second click/tick when idle

According to WD, this irritating noise is a ‘feature’ of their newer drives; there are quite a few threads on this kind of thing all over the place: e.g. Periodic Noise from Head Movement WD Black 4TB - #29 by MikeVeltri

Make sure to create a support ticket or return your drive so that WD know that it’s just plain stupid for an idle drive to be making this kind of noise so regularly.