Every mom knows how fast a cold can spread from one family member to another. But moods can be just as contagious. The other day, my 4-year-old, Joe, started wailing because his 6-year-old brother, Henry, refused to share an old piece of Halloween candy he'd found. Sam, 11, was yelling at me to make Joe be quiet so he could listen to his Beatles CD for the 45th time. And Henry was begging, "But why can't I eat it if supper isn't ready anyway?" I practically went through the roof, even though I'd been perfectly content three minutes before.

Although we're not always aware of it, we can't help but feel one another's emotions. Research shows that even a stranger will respond unconsciously to the sound of a baby's cries: His heart rate speeds up, and his blood pressure rises. If unrelated people respond this way to another person's distress, how much more so do we affect one another in our own home?

Meltdowns are inevitable in any family; the trick is to keep them to a minimum. Here, moms share their hard-won solutions for keeping the peace. (May they inspire some it's-not-too-late New Year's resolutions for making your own home even happier!)

Feed the hungry. Kids don't always recognize when they're hungry. Instead of saying calmly, "I need a snack," they just get fussier and more likely to blow up at the smallest thing. So I've learned not to let blood-sugar levels drop to the breaking point. I keep granola bars in the car, string cheese at kid level in the fridge, and bananas on the kitchen table. If someone gets whiny for no apparent reason, I hand out a snack, even if dinner will be on the table in ten minutes. And since I get fussier when I'm hungry, too, I make sure I eat mini-snacks myself.

Margaret Renkl is a contributing editor to Parenting.