Close Encounters of the Learning Type

Along the narrow corridor, through the open door,
Lurks the home of a very strict, mysterious creature,
And this creature is extinct in the wild,
For they have all swarmed to the zoos,
Where they keep the babbling young at bay,
And drink and eat in their dens,
Licking the wounds of the day,
And when they return to their home,
They chill out and put their feet up,
For this creature is known by one word,
Teacher.