Question

How did the creatures of the bog get attracted to the sumac tree and why did they stop coming there at the end

Answer 1

Firstly the creatures were attracted to the sumac tree because the nightingale was sitting on it and was singing a very beautiful and mesmorising song. Her voice was melodious.
But in the end everybody stopped coming to the sumac tree because the frog exploited her voice and her voice had turned from soft to rough. Her voice was no longer attracting anyone.