Physical Development

Each year, more than a million children are treated for injuries related to safety hazards in the home. The most common injuries include burns from uncovered radiators or too-hot bathwater, poisonings from ingesting toxic substances such as household cleaners, and falls. To prevent these and other disasters, it is imperative that you childproof your home and provide proper supervision for baby at all times. Childproofing also allows your child greater freedom to explore (since fewer areas are off limits) and more independence of movement, which help build self-esteem.

Before you rush off to the mall to buy safety gadgets, make a list of what you'll need. Experienced parents agree that the best way to identify potential problems is to take a baby's-eye view. You guessed it: Get on your hands and knees and crawl through every room in your home. Don't forget the backyard, deck, pool area, and anyplace else baby can wander. Count the electrical outlets, take note of the sharp edge at the bottom your kitchen counters, and see if you can get the oven open (don't underestimate your child's motivation--enterprising babies have been known to work for an hour to gain access to a forbidden area). Make the list as you go along. Absolute "musts" include:

• Wall-mounted (not pressure-mounted) gates for the top and bottom of stairs.
• No-slip strips and a cushioned faucet cover for the bathtub. You'll also want to turn the water temperature down to 120 degrees--anything hotter can scald baby.
• Screens or covers for all heat sources.
• Safety latches for drawers and cabinets; it's also a good idea to move toxic substances to high cabinets rather than leaving them, say, below the sink.
• Outlet covers and shields or covers for electric cords (cords should never be left in baby's reach).
• Smoke detectors and a fire extinguisher.

Social Development

Although they turn on the charm for brothers and sisters, most 9-month-olds would rather play with a toy than with another child. Two babies placed side by side will engage in parallel play, each enjoying his own toy but not interacting with the other. It will be at least four months before your child realizes that playmates are the best toys of all.

Intellectual Development

You'll find your baby a bit harder to amuse these days. Now that he can remember games and toys from one day to the next, he'll quickly grow bored with repeated stimuli. This is a good time to start rotating his toys (put out a few at a time, then switch every few days). Put a basket of toys in each room he frequents, and let him spend time with each of them.

Note: The information above offers general guidelines, but all babies develop differently, and few hit their milestones precisely when the conventional wisdom says they should. If your child was born prematurely, you may want to use your due date as a baseline for following baby's development.