It's unannounced leftover food, isn't it? Can't be beaten.

(Thinly veiled "just ate a handful of crisps, a token grape and a corner slice of brownie" thread.)

My gf said that last week a dog got into the corridor outside the conference room she was having a meeting in (they get a lot of dog walkers around the business park and one must have gotten away from its owner). Dog! In the office! No reports of people standing around chanting "Shearer! Shearer!"