The above animated video show insect sizes in comparison to each other. To portray the insects at a human scale, he concocts a scenario where space aliens land, zap the bugs with an embiggening ray, where they then rampage about causing mayhem. I felt sorry for the poor office workers who got stuck in the spider's web.
Come to think of it, this would make a pretty good plot for a Sci-Fi channel movie of the week. They might even be able to top the CGI of this video. They would need a washed-up actress to play the female lead. Rachel Zegler comes to mind, now that she tanked her career, she probably could come for cheap.