In the classroom you expect various things. However, somthing which you have to get used to are the legions of bugs which descend each day. There are bloody millions of them.
So, there you are teaching, the class is working quietly, and before you know what is going on all hell breaks loose. A hornet/bee/wasp/whatever, which is the size of an old fifty pence piece, decides to arrive in the classroom. And worst of all, I am supposed to be calm and know what I'm doing, because I'm the teacher.
These create the most commotion, but for sheer scale of insect, some of the beetles have to be seen to be believed. On Monday, the class and I were walking back from the assembly hall. Suddenly, there was a great deal of shouting. I discovered the reason was a beetle that was a good two inches long. Almost of of the class were in pieces. You just can't plan for this kind of thing.