How to dissuade a neighbour's cat from loitering on our property?

As per the subject, How to dissuade a neighbour’s cat from loitering on our property? This little mongrel Ciara is feeding off the poor little sparrows that inhabit our surroundings and then leaving some of their respective remains at our back door. We know the cat is trying to impress us, but seriously, we are this close to feeding the little girl some bitrex cat nips. Any humane suggestions before we send little Ciara to another place like heaven? We would have no problem doing that.