The first year of your baby's life is definitely more like a marathon than a sprint. You'll probably find that as your baby gets older, time goes faster thanks to all the new stuff your tiny genius is picking up along the way. Soon you'll be watching her walk across a stage to collect her diploma, but for now, how about working on just learning to walk? She'll probably start taking her first steps in the next few months, along with a ton of other developmental milestones that you can help her reach.

Develops Separation Anxiety. While in previous months your little one was more than happy to engage with complete strangers in the grocery store, don't be surprised if one wrong look suddenly sends her screaming. Babies start to fear strangers around 9 months, something that comes with learning and age. Her favorite companion is you, making babysitters and bedtime tricky to maneuver.

  • Offer a comfort item that your little one can keep with her at all times. A small toy or a special blanket can make her feel comforted around strangers, when she's alone in her room, or any other time that you're not around.
  • Never punish your baby for being clingy. Instead, offer extra hugs and reassurance when she's feeling nervous, especially when you're around a lot of other people. Helping her feel secure is the best way to nip separation anxiety in the bud.

Can Use Sign Language. If you've been using sign language with your baby, you'll finally start to see your hard work and consistency pay off. Nine months is about the time where your babe can sign back to you, which eliminates some of the power struggles and frustration stemming from poor communication. Armed with a few simple signs, you'll actually know what she wants.

  • Give up the goods as soon as she asks for them. If your baby starts signing for milk and you ignore it, she'll learn that signing doesn't give her results and she'll lapse back into crying for the things she wants.
  • Be as consistent as possible. It helps to teach family members and caregivers the various signs that you use on a regular basis. Not only will it help them get your baby what she needs, but it'll eliminate meltdowns and frustration as well.

Responds to Commands. All of the directives you tried to give before this point can be chalked up to practice. Whether you're an expert at saying "no" or you've tried to get your babe to clap or show off a gummy grin for others, children younger than 9 months don't really understand commands. Now, she'll figure out how to respond to short pieces of information to help open the lines of communication.

  • Keep commands short and to the point. If you want your baby to understand, a command shouldn't have more than one or two steps. Telling her, "Be nice to the dog" is confusing because it's too abstract. Instead say, "Pat the dog nicely," and demonstrate what you mean. It's way easier for her little mind to grasp what you want her to do and how to do it.
  • Save "no" for the big stuff. When you're constantly using the n-word, your little monkey eventually tunes it out. Instead of being negative, try redirecting your babe's attention, saving "no" for when her safety is at risk.

Loves Games and Music. Before, your baby mostly enjoyed spectator sports. She loved to watch others play, but couldn't really join in the fun. Expect her to be a more willing participant nowadays, particularly when it comes to singing songs with actions, playing peek-a-boo, or trying to find an object that you've hidden.

  • Engage your baby as much as possible. Pediatrician Dr. Tisa Johnson-Hooper suggests the following activities: "Read to baby everyday, play cause and effect games, and listen to music and dance." To your little one, playtime is near-perfect stimulation.

Masters her Movement. Younger babies often get around with jerky movements, hoisting their body weight to move. A 9-month-old gets way more adept at moving around, so your little one becomes a smooth operator in no time. Whether it's crawling, cruising, or first steps, your baby is learning to master her body.

  • Give her plenty of time to practice. Fencing off a guarded area of your home and allowing your tiny cruiser to practice moving helps her test out her new skills in a safe environment.
  • Anchor all heavy furniture to the walls with anchoring kits that you can purchase from a hardware supply store. That way, when your little explorer is getting around from pont A to point B, she can do it safely; falling furniture can be fatal for fragile children.

Sleeps Through the Night. Ah, the bliss a full night's sleep; you should be enjoying that right about now. A 9-month-old is old enough to sleep through the night without waking for a feeding, so if your little one isn't giving you much rest, it's a great time to focus on sleep training.

  • Plan for little things that could disrupt your little one's sleep schedule. Even something as minor as a vacation, an ear infection, teething, or a new environment could turn a great sleeper into a midnight alarm clock. Remember, it'll take time for your babe to settle back into her schedule again.
  • Make your baby's sleep environment as conducive to dreamland as possible. Dim lighting, white noise, and a consistent bedtime routine all help to make nighttime less stressful for everyone involved.

Gets Sick More Easily. One surprising thing that you might notice this month is an upswing in illnesses. A 2011 study published in an issue of Human Vaccines noted that a young baby's health is protected by maternal antibodies that the little one receives in utero. After the first nine months, those antibodies wear off, leaving your baby more susceptible to common, but uncomplicated, illnesses.

  • Keep surfaces in your home as clean as possible, and disinfect your baby's playthings on a regular basis. When an infant finds a new toy or object, it goes straight into her mouth! Transferring bacteria from her toys to her mouth is one of the fastest ways to get sick, so make sure the stuff she gets her hands on is clean.
  • Relax. The most common illnesses that babies deal with are colds, the flu, and ear infections. You'll only need to bring your little one to the doc if she has a fever over 102 degrees Fahrenheit, exhibits signs of pain in her ears, or she seems lethargic and won't eat or drink. Other than that, you can just work to keep your babe comfortable until the illness is over.

See a difference this month? You should; it was only a couple months ago that you were worried about rolling over and offering food for the first time. Now it's all about playtime and keeping your active infant totally stimulated all day long. Luckily, her natural curiosity paired with your parenting skills makes for a happy, healthy baby.