They wake throughout the night, racing about, whirring, humming, hooting and jumping into their mother's bed. She is lucky to get four hours' uninterrupted sleep. They have fits of tearless crying - making a 'banshee wail' for protracted periods. They simply cannot understand the concept of the word 'no'. George tears sweet wrappers into tiny pieces; Sam rubs balloons together, making irritating squeaky sounds.