Invasion by Air and by Land

We have an infestation at school: of pigeons AND rats. There is a hole in the ceilingt tile above the chalkboard and it is constantly raining down insulation, feathers, and bird droppings. Each morning I sweep up this nasty debris but I am fighting a losing battle. There is a nest above my desk and we often hear chirping and scraping coming from the ceiling. And in the far end of the hall where I teach there is a pile of extra desks and chairs where rats like to congregate. I try not too look too closely but the other day I couldn't help noticing a dead rat on the ground. I don't know if it was killed by the school cat or if it died of natural causes, regardless it was really nasty. I am tempted to bring a plastic snake and throw it up in the ceiling to see if I could scare them away but I could see that ending badly. If a snake (even a plastic one) fell from the ceiling it would probably freak out the entire class. For the time being I keep watching the floor and the ceiling for various pests.