"A class should divide into 2 teams" or "A class should be divided into 2 teams"?
And one more question.
"improve knowledge of domestic animals" or "improve knowledge about domestic animals"?
 A class should divide (themselves) into 2 teams.
Meaning, on their own, by themselves.
 A class should be divided (by the teacher) into 2 teams.
Meaning, someone tells them to do it.
Could you give us the complete sentence for this example?
Ex: ... improve knowledge of/about domestic animals