Classroom Pet... (alieliza)

How about a soft billed bird like a dove or finches??  They can't hurt if they try to bite and they are pretty quiet--the dove makes a nice cooing sound when they do make noise and the finches sort of make a quiet beep, beep sound. 

A properly sized cage for a rat usually rules them out for a classroom pet, especially as they should really be kept in same sex pairs.  They need a lot of cage room to be happy and healthy.  They are indeed great pets, and space issues aside they'd be great class pets.

 I love guinea pigs too, but they also require a great deal of room to be properly housed.

Many of the dwarf hamsters are pretty lively and entertaining They require proper housing, but it need be nowhere near as large. They can also be housed singly. They do many times adapt their sleeping schedules and can be more active during school hours, especially if people are up and about.

Just a heads up on critters like degus and dwarf hamsters- some states require that you have a permit for them, along with other critters.  And sometimes what you need permits for doesn't make sense- here in NJ, I don't need a permit for a hamster or red tailed boa, but need one for a dwarf hamster and python (nope, no snakes here, but know people that have them).