In a high tech future, small insect-sized robots are used for corporate espionage & sabotage. This is the story of the adventures with these nuisances the nightly cleaning crew of an office building has been recently facing.
Ending is unnecessarily anti-Physics: these robots are powered by the friction with surroundings of their own movements in parallel universes! Don't ask me where the power to move came from in those alternate realities.
Except for last few paras, it's generally an ok read.
Fact sheet.First published: George Mann (ed)'s "The Solaris Book of Science Fiction, Volume 3" (2009).
Download full text from author's site.
Nominated for BSFA Award 2009 in short fiction category.
Related: Stories of Ian Whates.