Gargoyles - Serving a Dual Purpose

Last week during class we covered a lot of interesting material and of all those topics what caught my attention?  Gargoyles so I did a little research and it turns out they served a dual purpose, in some instances they were intended to scare away birds from nesting on the roof and to divert water away from the face of the building by a hole in the top of the statue which either expelled the water through the face of the gargoyle or out the back just think of them as a really big gutter.