Most schools are generally not allowed to keep pets, because keeping pets will destroy the dormitory environment and easily lead to the spread of diseases. Especially those stray cats and dogs who don't know where they are. If we adopt them in the dormitory, what if they bite rabies or something? At this time, the school will bear a great responsibility.
Many students are not aware of this problem, so they feel that the school is particularly ruthless in this respect. In fact, schools should consider their own interests on the one hand, and protect the safety of other students on the other, so they are more principled on these issues.
Of course, if you don't let him see it, or what you mention is irrelevant, people won't come to take you. For example, if you put two hamsters in a small cage, they won't do any harm. You regularly change sawdust, feed it and bathe it. This series of operations will not cause too many problems and will not pollute the dormitory environment. When others come to check, they basically can't smell anything, and they won't rob you again.
But if you keep an animal with a particularly strong smell, such as a rabbit, it smells like two or three dormitories around you will vomit, so this thing is not allowed to be kept. In addition, dogs, especially large dogs such as golden retriever and husky, are basically not allowed to keep, and cats may be better.
Animals that can be kept are hamsters, parrots, turtles, goldfish and so on. These relatively small animals are not prone to problems and are not very troublesome to manage, so they can be kept. In addition, those reptiles and snakes and lizards are not allowed to be kept, and may even be found in informed criticism.