Your first clue that something is up might be when your preschooler says, "Kids are mean to me." Or "I hate so-and-so, and I don't want to play with him anymore." In my case, the eye-opener was when my son, Kevin, brought home his preschool class picture. As he pointed from one smiling child to the next, he told me, "That's Thomas, that's Riley, that's Jenny, that's..." (ominous drumroll, please) "my bully, that's..."

Whoa there, little fella, back up. Back way up. A bully? In a preschool class of 3- and 4-year-olds? Don't bullies have to be older -- or at least capable of opening their own milk at snack time? I scrutinized the image of the brown-haired, blue-eyed boy standing in the back row in the photograph. He wasn't scowling, and he didn't have Bluto-like muscles bulging underneath his ordinary little T-shirt. The "bully" didn't look like a bully at all; he looked like a little kid.

Still, the mama bear in me wanted to march right over to the school, grab that pup by the scruff of his neck, and tell him that if he kept harassing my kid, he wouldn't live to see his fifth birthday. Rest assured, I did no such thing. But my protective impulse was fueled by Kevin's stories of being banned from the playground pirate fort and pinched during circle time. Maybe not life-threatening things, but definitely not nice either. And as it turns out, my son is not alone.

Not too young to be a bully

With school bullying consistently in the media spotlight, most parents are aware that it's a serious problem. That's encouraging -- but we're forgetting about our youngest and most vulnerable age group, the toddler and preschool crowd.

We once thought these kids were too young for the kind of tormenting we associate with bullying. But sadly, that's just not true -- and because little-kid bullying is so surprising to many parents, it's not noticed as readily as in older kids, says Henry D. Schlinger, Ph.D., director of the applied behavior analysis program at California State University at Los Angeles. Adults dismiss it as "kids being kids."

It doesn't have to be that way, and that kind of attitude ignores the very real developmental leaps kids make in late toddlerhood. Before age 3, kids don't have the cognitive ability to feel empathy, says Brenda Nixon, a mom, former preschool teacher, and author of The Birth to Five Book. So a child might hurt another kid emotionally or physically, but he doesn't really get how that feels to his playmate. You can't really say that he's being mean. After 3, that changes: "The brain has the ability to understand another point of view, so that's the age that premeditated and purposeful aggression could begin," says Nixon. In other words, these little troublemakers should know better.

The reasons kids bully vary, says Schlinger. "Often kids this age are imitating behavior they've seen before" from a parent, sibling, or friend, he says. Other kids turn to bullying to get attention, either from adults or peers. Still others bully for more complex reasons. "It's much more concerning when a child bullies because it makes him feel good to see signs of injury, fear, or misery in his victim," says Schlinger. "That type of bully can be hard to stop."

Too often, parents and even teachers take a wait-and-see approach with preschoolers. That's not helping anyone -- the bullied kid or the bully. "The problem with ignoring smaller incidents is that intervention doesn't happen until it reaches a crisis point or someone gets hurt," says Schlinger. Ouch! I was guilty of this. Before showing me his school picture, my son had told me time and time again that a boy was "bothering" him, and I'd dismissed it.