Children's Age-by-Age Guide: 3 to 6 Months

Physical Milestones

Between ages 3 and 6 months, your little one will begin to reach for objects, try to grasp them, and put anything in his mouth that he can. He'll roll over, in both directions (so never leave him on a high surface, like a bed or changing table, even for a minute!), and will squirm when left alone on the floor or in his crib. Around 4 months, he'll be taking in about 40 ounces of milk a day, and he'll drool a lot (you'll make good use of all those bibs). He can swallow now, and soon his first tooth may appear. He'll also be able to sit up, with assistance. These are all signs that he'll soon be ready to tackle solid foods.

Smart Strategy:

Rice cereal is a good first cereal for baby, and can be mixed with breast milk or formula. After a few weeks, you can introduce pureed veggies and fruits, one at a time. Watch for these signs of allergies: watery eyes, difficulty breathing, runny nose, coughing, fitful sleep. Report any signs to your pediatrician.

At this age, playtime becomes more and more important to your baby. She loves when you interact with her, especially when you pull her up to a standing position. She likes watching her crib mobile, playing with her hands and toes, and looking at herself in the mirror. She also enjoys making noise by swatting at toys and is content to do it over and over. You can expect to hear plenty of coos and gurgles. Your baby is aware of herself, but needs you to expose her to different settings so she can begin to adapt to change without getting too upset.

Smart Strategy:

Amuse your baby by introducing toys that move and make noise. Encourage her constant banging and throwing because that's how she learns cause and effect. Vary her toys as much as possible by giving her different choices at different times. Place some playthings just beyond her grasp so she has to reach for them. Most importantly, be sure anything you offer her is safe to put in her mouth because that's exactly where it will end up!

Emotional Milestones

When you look at your baby, he's likely to smile at you, open his eyes wide, and focus his attention on you. He'll even giggle if you make a funny face. At this age, he recognizes you and is learning to interact with his world. He may even begin to show attachment to a particular toy or object that makes him feel good when he holds it (this is a sign that he is beginning to take interest in things outside of himself). He can amuse himself for short periods of time in his crib, swing, or infant seat. Allow him some "alone time" so he begins to realize he can do things for himself.

Smart Strategy:

Woo your baby -- smile, talk, cuddle with him, but not all at once or he may get overloaded. The point is to get him to interact and explore the different feelings that are beginning to surface. He'll react to your tone of voice -- he'll be upset with an angry voice, pleased with a happy tone.

Your little one is beginning to realize that you exist even if she cannot see you -- this is called object permanence. Help foster this understanding by playing games like peek-a-boo. She'll also start to learn cause and effect now; she'll drop toys and look for them, bang and rattle every object she can hold, and she'll be extremely pleased with herself as she performs these acts and looks to you for approval. Since she is gaining a sense of awareness of the differences in people, she may start to show stranger anxiety. Even if she didn't mind being held by others in the past, she may fall apart now if Grandma holds her or Uncle Joe gets too close.

Smart Strategy:

Now is a good time to start reading to your baby. She won't be able to understand each and every word, but she'll respond to the photographs (especially if they are of other babies) and love to turn the pages of board books as she listens to your voice. Choose books that have bold, bright colors and simple pictures of familiar objects. Babies this age love nursery rhymes because the rhythm fascinates them.

• 1 to 4 months-the second dose of Hepatitis B (Hep B). It must be given at least one month after the first dose.
• 4 months -- Second dose of Diphtheria, Tetanus, Pertussis (DTaP)
• 4 months -- Second dose of H.influenzae type b (Hib)
• 4 months -- Second dose of Inactivated Polio (IPV)
• 4 months -- Second dose of Pneumococcal Conjugate (PCV)