The smooth movement of hands to mouth (with objects now in tow!)
Your baby is likely to have been putting their hand in their mouth since they were born, but you might notice now that they can do this more accurately, bringing their hand up quite smoothly. When they are holding a toy, they may also try to put it into their mouth; of course they won't be able to get this right every time and might sometimes bump their chin rather than reaching their intended destination.[1]
Developing control
Your baby’s fine motor and gross motor skills are closely linked as initially they will use movements of their arm to position their hand to grasp and explore items.[1]
As your baby’s physical skills develop, they will continue to use their arm for support, to position their hand and to adjust the force that they use when doing things.
Now, your baby is developing the control and awareness of their movements needed to place their hand in a particular position, and you'll be seeing this in action when they bring their hand to their mouth or move an object towards it.
Links with other streams
Developing a skill in one stream often links to skills in others, so greater control of their arms and hands supports your baby to learn about the world as they use all their senses for exploration.
Cognitive: Exploring with their mouth
Your baby’s sense of touch was one of the first senses to develop before they were born and the development started with their mouth.[2]
Your baby will use their mouth to investigate objects and this will help them to explore the texture and shape of objects for some time.[2]
Exploring objects with their mouth helps your baby to learn about toys and objects and putting their hand in their mouth can provide comfort, but also contribute to their developing sense of their body.
Language: Mouth movements
Moving their mouth in different ways will help your baby to develop the muscles and control that they need to make sounds and to say words.
When your baby explores their hands or an object with their mouth, they can move their lips and tongue in different ways and develop control of their mouth.[3]
Sensory: Awareness of their body
Your baby will also start to link their growing awareness of their body with their movement. They will be able to move their hand towards their mouth because they have the control to do this, as well as the awareness of their body that's needed to bring their hand to their mouth.
This seemingly simple action will begin to make wider connections between their senses. Your baby will link what they see with what they feel with their mouth and hands, and begin the fascinating journey of learning about themselves and things in the world around them.
Reaching, grasping, holding and looking!
Your baby will continue to develop control of their movements and in the next few months will be able to reach for and grasp toys and objects. They will bring them more accurately to their mouth and as their physical skills develop they might hold an object and look at it before putting it into their mouth.
References:
[1] Sugden, D & Wade, M. (2013) Clinics in developmental medicine. Typical and atypical motor development. London: Mac Keith Press.
[2] Goddard-Blythe, S. (2004). The Well Balanced Child: Movement and Early Learning. Stroud: Hawthorn Press.
[3] Gotzke, C. & Sample Gosse, H. (2007). Research Review: Vocalizing 0 - 3 Months. In L.M. Phillips (Ed.), Handbook of language and literacy development: A Roadmap from 0 - 60 Months. [online], pp. 1 - 8. London, ON: Canadian Language and Literacy Research Network. Available at: Handbook of language and literacy development