It's the annoying clock in the corner that continues to tick every second of every hour of a long day.
Absent and silent whilst active or watching TV, but the minute you go to rest or sleep it is all you can hear or think about.
WHY DO YOU TICK? You tick me off.
Although, it appears some people find this relaxing and calming (who are you). Well try being stuck in a room with a Grandfather clock that chimes the time every 15 minutes, and continues to belt out a woodpecker tick every second. Try dealing with that without it getting on your tits