Between five and seven months, your baby becomes an investigator. Everything gets grabbed, examined, and put in the mouth. Object permanence is emerging — which means they now know you exist when you leave the room and respond accordingly. Sitting arrives. Weaning begins. Stranger anxiety makes its first appearance. This is one of the most developmentally rich stages of the first year, and one of the most practically demanding.
🔍 Track this stage in your Baby DiaryBetween five and seven months, your baby becomes an investigator. Everything within reach gets grabbed, transferred from hand to hand, inspected, and put in their mouth. They are watching you eat with focused attention. They are beginning to understand that objects exist when they cannot see them — the cognitive shift called object permanence that transforms how they experience the world and the people in it.
This is also the stage when weaning begins for most families, when sitting arrives, and when stranger anxiety often makes its first appearance. Your baby is becoming more distinctly themselves — with preferences, opinions, and the beginnings of something that looks very much like a sense of humour.
Independent sitting — sitting without any support for more than a few seconds — typically emerges between six and eight months, with considerable normal variation. It develops through a progression of stages that cannot be rushed but can be supported.
Starting solid foods is one of the most anticipated and most anxiety-provoking milestones of the first year. The NHS recommends starting at around six months — not before four months under any circumstances, and ideally at or close to six months when the baby's digestive and immune systems are more ready.
Readiness is defined by three specific developmental markers — not age alone, and not the commonly cited signs that are actually unreliable indicators:
There is no specific order that foods need to be introduced in — the goal is variety and gradual progression. Iron-rich foods are important from the start because the iron stored from birth is depleting: red meat, dark poultry, lentils, beans, and iron-fortified cereals are all good sources. Vegetables, fruits, and carbohydrates can all be introduced freely.
The six most important allergens to introduce early and keep in the diet are: cow's milk (in food — not as a main drink before 12 months), eggs, peanuts, tree nuts (ground or as butter), wheat, and fish. Current evidence strongly suggests that early introduction — before 12 months — reduces the risk of allergy developing. Introduce one new allergen at a time, wait 2–3 days before introducing the next, and offer at a time of day when you can observe for reactions for a couple of hours.
If your baby has severe eczema or a known egg allergy, speak to your GP before introducing peanut, as they may need a supervised introduction.
Both approaches work. Baby-led weaning — offering soft finger foods from the start rather than purees — has good evidence for developing fine motor skills and a positive relationship with food, but requires careful attention to texture and choking risk. Purees allow more control over texture progression and may feel safer initially. Most families use a mixture of both. The right approach is the one that works for your family and your baby.
Stranger anxiety — the distress your baby shows when approached by unfamiliar people, and increasingly when separated from you — typically begins between 5 and 8 months and peaks around 8–10 months. It is one of the most commonly misunderstood developmental events of the first year.
It is not a sign that your baby is shy, anxious by nature, or not socialised enough. It is a direct consequence of cognitive development: your baby now has clear mental representations of familiar people (primarily you), understands that unfamiliar people are not you, and has the emotional response to that awareness that you would expect from someone encountering a stranger for the first time. It is developmental, it is normal, and it passes.
First teeth typically emerge between 4 and 7 months, though anywhere between 3 and 14 months is within the normal range. A minority of babies are born with teeth; some do not get their first tooth until after their first birthday. Neither is cause for concern.
Increased drooling, fist and object chewing, gum tenderness and swelling around erupting teeth, some increased irritability, and mild disrupted sleep around the time a tooth breaks through the gum. These symptoms are real and often uncomfortable for your baby.
Fever, diarrhoea, nappy rash, or significant illness. These are common folk attributions that have been disproved by research. If your baby has a temperature above 38°C or is significantly unwell, do not attribute it to teething — investigate it.
Sleep during this stage is highly variable. Some babies consolidate night sleep significantly; others continue waking frequently. The range of normal at 6 months is enormous — from sleeping through to waking 4–5 times — and neither end of that range says anything about your parenting.
If you want to make changes to night waking at this age, 5–7 months is considered an appropriate window to begin gentle sleep coaching. Your baby has the neurological capacity to begin settling more independently, and the AAP notes that responsive approaches begun after 4 months do not cause harm to the parent-child relationship. The NHS does not recommend any specific approach; consistency and your capacity to sustain the approach matter more than the method.
Daytime sleep at this stage is typically 2–3 hours across two naps. Some babies are beginning to consolidate from three naps to two around five to six months.