1) they have a reflex called Moro reflex (startle reflex), where their arms and legs will go up in the air when they’re startled, and they’re very easily startled. What can help to keep your baby feeling more secure is if you swaddle your baby well. This reflex normally disappears by about 6 months. It’s already much less by 3-4 months.
2) At 6 days old, your baby’s sleep cycle is very short, so baby goes from light sleep to deep sleep, back to light sleep again very quickly. Maybe even 15-20minutes... so baby may appear to be half sleeping since baby will keep waking up. If baby goes back to sleep, then that’s great. That’s chaining the sleep cycles together. Makes everybody happy. Haha. The sleep cycle will gradually lengthen as baby grows older, and baby will also be more sound asleep (deep sleep) for longer periods
Jai Kishore