I have several clients who are school teachers, and several of them have pets in the classrooms. Typically this will be a hamster or other small mammal, but sometimes it extends to reptiles such as bearded dragons and ball pythons. In all of these cases I think that a classroom pet can be a great educational experience for kids and can give a broader set of experiences than you might think.
Last month one of my clients (a teacher) brought me her classroom pet, a ball python. He was having some mild wheezing and she wanted to make sure he was okay, especially with Christmas break coming up. I diagnosed him with a mild respiratory infection and prescribed him some antibiotics. During that visit and at the follow-up a few weeks later we talked about Marvin (the snake) in relation to her classroom. Of course she was using him as an example of animal care and biology. But she expanded the lesson to include math and the metric system, talking to her students about how to calculate dosages, stressing the important of math in the medical profession, and reviewing the volume measurement of the medicine. She took pictures of me with Marvin (as she often does when she brings pet in) so that she could share them with her class and post on Facebook, and kept her students updated even while on break.
I really admire how she and other teachers find learning opportunities in even the most simple things. A snake with a minor infection became a lesson in anatomy (snakes only have one functional lung), the responsibilities of pet care, the medical reasons for increasing temperature and humidity during an illness like this, math calucations for medications, and so much more. Her students and friends followed Marvin's progress and he did get better. But beyond the healing of a pet snake there were many things that the students learned.
Teachers like this are to be cherished and honored. They are the ones who really take the time to teach beyond what is in the lesson plan or text book. One of the things that always bothered me when I was a student (even though college and graduate school) was that many things really didn't seem to matter in the "real world". I had to take two semesters of Calculus in college as a prequisite for entering vet school, and I have no idea why. I made A's in both classes but still to this day can't tell you exactly what calculus is and when it should be used. I definitely can say that I've never needed it in my veterinary education or career. So why bother? Many students feel this way about subjects like math and biology, so showing them the practical applications is important. Much of what is taught in school really does matter, but when it comes down to book exercises and rote memorization the reasons for learning the material can get lost.
That's where good teachers come into play. Ones who take the theory and texts and apply them to every day life. They have my admiration.