By the end of the third month, most babies will:

• Recognize the sight and voice of their parents
• Smile in response to seeing or hearing their parents
• Become interested in more complicated visual patterns
• Become interested in strangers’ faces
• Develop more head control
• Sleep in longer blocks of time
• Tend to reach toward or grab objects more often

By the end of 6 months, your baby should:

• be able to focus on small objects
• look toward the source of sound
• repeat and babble simple sounds made by the user
• eat less often and practice eating solid food
• play alone for long periods of time before crying
• begin examining the world with their hands

By end of the ninth month, most babies will:

• look for toys which have moved out of sight
• become upset when you say good-bye and leave
• try to imitate your words by babbling
• move more independently, learning to crawl and/or pull up
• begin to manipulate and understand how objects work

• Sitting Independently: Achieves the ability to sit without support (usually by 6-9 months). This is a foundation for all subsequent upright movement and frees the hands for play.
• Pincer Grasp: Develops the skill to pick up small objects using the thumb and forefinger (usually by 9-12 months). This fine motor skill is crucial for self-feeding and exploring small toys.
• Crawling or Cruising: Achieves some form of self-locomotion (crawling, scooting, or pulling up and walking while holding onto furniture, known as cruising) to independently move around the room.
• Basic Communication: Understands and responds to their own name and the word "No," and may start using simple gestures like waving "bye-bye."
• Object Permanence: Demonstrates an understanding that objects still exist even when they are out of sight, typically by looking for a hidden toy (a key cognitive step, usually established around 8-10 months).