On returning to England, Darwin and an ornithologist associate identified 13 species of finches that he had collected on the GalÃ¡pagos Islands. This was puzzling since he knew of only one species of this bird on the mainland of South America, nearly 600 miles to the east, where they had all presumably originated.
To get the most out of a nap, follow these tips: 1  Keep naps short. 2  Aim to nap for only 10 to 30 minutes. 3  The longer you nap, the more likely you are to feel groggy afterward. 4  Take naps in the afternoon.
Limit naps to 20 minutes (see my last tip for an alternative). Napping for longer than 20 minutes can allow the person to enter deep sleep and to then wake up from deep sleep. Sleep inertia lasts longer and the effects are worse when you wake up from deep sleep. Avoid napping between 22:30 and 04:40 hrs.