Nappy time:

Kurt Kleiner: The modern world killed off the nap: A tribute to the soft pleasures of dozing, backed up by hard science.
As a species, we seem designed to nap. Sleep researchers have long known that our natural circadian rhythms show two distinct dips in energy and alertness. The major dip starts in the late evening, helping us get ready for a good night's sleep.
But there's another significant dip in the early afternoon that, in a saner world, would have us all dropping off. From an evolutionary point of view, this pattern makes some sense — our ancestors evolved in the tropics, where a desire to sleep during the hottest part of the day probably helped ensure survival....
MetroNaps sells naps as a productivity-enhancing experience for office workers, one that will send you back to your high-powered job with a better attitude and a better ability to get the job done.
If that's what it takes to pry a little room out of the day for more napping, I'm all for it. But for me, the productivity enhancement is almost beside the point. It's as if someone were arguing that I should eat lunch so that I could work harder.

I always feel a little sleepy after lunch. Maybe I should stop fighting it.