When you consider the possible scenarios that lead to a kid getting kicked out of school, what likely comes to mind is out-of-control teenage rule-breaking.

In reality, unexpectedly high numbers of those sent home from many metro-area schools are just 4 and 5 years old. That's what the data showed when Minneapolis schools ran the numbers earlier this year. In response, district leaders have appropriately changed policies.

During the first week of the school year, Minneapolis Superintendent Bernadeia Johnson told staff that prekindergarten, kindergarten and first-grade students may not be suspended or expelled for nonviolent behavior. Minneapolis joined many districts around the nation that are changing policies on discipline.

The administration is right to do more to keep the city's youngest learners in school. At the same time, leaders must be sure to protect the rights of those kids who behave themselves in class.

The needed focus on suspensions of the youngest students emerged as local and national research confirmed that educators tend to disproportionately suspend and expel students of color. Last March, a federal Department of Education Office of Civil Rights report examined disciplinary practices in the country's 97,000 public schools. That study showed that excessively punitive policies are being applied throughout the public schools system.

African-American students, for example, are suspended at three times the rate of white students systemwide. And the new data show that the discipline disparities start early. Black children, according to the report, represent 18 percent of preschool enrollment but nearly half of all children who receive more than one out-of-school suspension.

In August, the Star Tribune reported that suspensions among kindergartners through fourth-graders in Minneapolis schools increased 32 percent, from 889 to 1,175, in the past year. Those numbers stood out compared to the other grades in which suspensions were down 10 percent from the previous year.

That 4-year-old children of color are being disproportionately suspended or expelled is especially troubling. That's the age at which they begin to learn the basic social skills they'll need to function in classrooms for the next 12 years. Suspending them at 4 or 5 goes against the purpose of early education, which is to prepare them for the higher grades. It also places children at greater risk of falling behind, dropping out or becoming permanently involved with the juvenile justice system.

It's almost always better to keep kids in school, where teachers can work to engage them rather than sending them home — in some cases to chaotic home environments that contribute to their problem behavior.

Regardless of the causes, there are ways to combat the problem. The Obama administration has called for more classroom management training for teachers and has issued guidance to school districts on how to avoid discriminatory practices.

Walter Gilliam of Yale University, who has studied the expulsion problem, suggests limiting enrollment to 10 students per preschool teacher, making sure that those teachers work reasonable hours and giving them access to children's mental health consultants who can assist them with the most difficult cases.

Other possible alternatives include in-school suspension, after-school detention or out-of-school classes that children are still required to attend. But the overarching policy should be that in all but the most egregious cases children will stay in school.

In addition to the suspension problem, Minneapolis schools have high rates of absenteeism among their youngest students. In 2013, about 46 percent of all kindergartners missed nine or more days of school.

At that age, children can't get themselves up and ready for school. Clearly too many parents and families don't make school attendance a priority. And it doesn't help that Minnesota law doesn't mandate school attendance until age 7.

For a child barely out of diapers, being suspended or missing a lot of school gets too many youngsters off to a terrible start. It's critical for parents to make sure their little ones get to school, and it's equally important for educators to keep them there.