Bron

The list that would make me go now rather than watch: sneezing, a runny nose or crusty eyes, breathing with his mouth open or with visible effort, sitting hunched with his fur puffed, eating less, weight dropping.

Respiratory infections are one of the more common serious illnesses in pet hamsters and they move fast in an animal that size, so with those it is an exotics vet promptly rather than at the weekend. Yours running and eating and rearranging at night is the opposite picture.

The difference is rhythm, and once you know to listen for it you cannot unhear it. Occasional squeaks with twitching paws, scattered and random, is dreaming. Plenty of mammals twitch and vocalise in deep sleep and hamsters are no exception.

A respiratory noise is attached to breathing. Click, click, click, one per breath, regular, going on as long as he is breathing. That is a different sound and it is the one that matters.