A stranger among you?

You may not know from one minute to the next how your 13-month-old will behave. Playgroups can be especially trying. Your toddler seems thrilled to see a friend, only to knock him down trying to get the toy he's holding. Or he may give that friend a hug before suddenly biting or hitting him. The simple explanation for this kind of behavior is that at 13 months, children don't see their playmates as people with feelings ? they are simply objects to explore.

At this age, many toddlers begin to behave unpredictably. Yours may scream at the top of his lungs for no apparent reason, pull the tablecloth (and all the dishes on it) to the floor, or yank the dog's tail despite your firmly telling him not to. Though this may be a trying time for you, remember that your toddler isn't deliberately disobeying you ? he's just exploring his surroundings and figuring out how much power he has over you, his environment, and himself. Many of these "destructive" practices will actually help him develop a sense of independence and figure out which types of behavior are acceptable to you and which aren't.

What you can do

You can help him channel his potentially destructive exuberance in safe ways. Pillow fights, for example, either outside or in a room where he can't break anything, are bound to tire out your toddler. For totally wild but nondestructive pillow fights, make a set of 12 small lightly stuffed pillows about 9 inches square ? they'll be easier for your toddler to heft and too light to break much of anything. Playing with modeling clay ? pulling, kneading, and rolling the squishy stuff ? is another good outlet. On the next rainy day, put on your rain boots and go jump in puddles together. If you're constantly admonishing your child to "keep the water in the tub," he'll love the freedom to splash around and make a big mess.

Other developments: Picky eating

Does your 13-month-old seem so busy he can't even make time to eat? That's because he's so preoccupied with moving that sitting still for five minutes, even to munch on a favorite food, may be more than he can manage on many days. Even if he eagerly ate everything from applesauce to garlic chicken when he was a baby, he may suddenly turn up his nose at every morsel you offer. Both behaviors are completely normal. You may think that because his activity level has increased so much he should be eating more, but a child's growth rate slows dramatically during the second year and that accounts for some loss of appetite.

Experts say it's a mistake to turn mealtime into a battle. The harder you push your child to eat, the less likely he is to do it. Offer him a choice of two or three nutritious foods at each sitting and let him eat what and how much he wants. (Be sure to offer him healthful snacks between mealtimes, too.) When he starts to throw food off his tray or otherwise play with it, take it as a sign that he's finished and remove the food. If he refuses to eat anything you put in front of him, wrap it up, put it in the refrigerator, and save it for later (but don't force him to eat the leftovers if he doesn't want to).