@Bi-Polar Bear,
Bear, if you want to kill them, don't do it badly... (sorry, I'm a proofreader).
I have always had cats and live trees and no problems. There were even some (unbreakable) round ornaments on the living room floor this year for days; they never moved.
Old mama cat just sleeps and eats these days; Young mama cat is mostly outside; I presume she plays with squirrels. And Kitten-boy snuggles with me or goes outside. He doesn't even trouble the birds any more - they were a real hit with him when they came to live here last summer.