Nine months. Your baby has now been in the world as long as they were inside you, which feels significant. They are a lot louder now. And more opinionated. Nine months is a brilliant developmental stage full of movement, communication, and the dawning realisation on your baby is part that they are a separate person from you, which leads to some very strong feelings. Most 9-month-olds are mobile in some way. Many are crawling, some are doing a commando crawl on their tummy, some are rolling around the room with impressive efficiency. A small number are already pulling to stand or cruising along furniture. Not crawling yet at 9 months is not necessarily a concern but mention it at your next check. Some babies skip crawling entirely and go straight to walking. That is within the normal range. Sitting is well established by 9 months. Most babies are sitting independently and confidently, freeing up their hands for play and exploration. Fine motor skills are developing rapidly. Watch for your baby picking up small objects with a pincer grip using just thumb and forefinger. This usually develops between 9 and 12 months. Language at 9 months is all babble but it is purposeful babble. Mama, dada, baba are common strings of sounds. Your baby is also starting to understand words. They know their name. They understand no, even if they choose to ignore it. Object permanence is really developing now, which is why peekaboo becomes even more delightful. Your baby knows you exist even when they cannot see you. This is also why separation anxiety tends to peak around 9 to 12 months.