#1. Children need lots of sleep, and when deprived of sleep, either by their own decision to wake up at 5am (or similar ridiculous hours repeatedly) or by that inflicted on them by their parents not providing a dark room for a nap while out for the day, they get grumpy. Or even grumpier depending on how grumpy they were to start with.
#2. Parents of children need lots of sleep in order to be able to cope with the grumpy children described above and to survive living in close proximity to many other people!!
Sarah and Tommy.