For the last two months I've been sleeping for 4 hours a night, thinking about Matthew Walker's "Why We Sleep". 130 hours of writing and research and 6000 words later:https://guzey.com/books/why-we-sleep/ …
re 'interlude' the original source for this statement on p38 is Siegel, J.M., 2008. Do all animals sleep?. Trends in neurosciences, 31(4), pp.208-213. https://www.ncbi.nlm.nih.gov/pubmed/18328577 . Pretty clear that all animals do not sleep, it is in the first line of the abstarct!