Killing a chicken

Yesterday we had to terminate one of our chickens - Godzilla - she was ill and old and not hopefully not a Bird Flu victim. I didn't do it myself - which I'm a little ashamed of - but got a friend to do it - a professional - but it didn't make it feel any better - in fact I felt guilty for not having the conviction to do it myself. It was a strange process that at every stage seemed loaded with meaning. I secretly hoped he would say something like - we'll leave it to the morning - or let's leave til after tea - but once asked the progress was slowly, methodically and unstoppably moving towards the final twist. I apologised for my using him to do my dirty work but he said that was how the noble profession of slaughtering came about - but again I felt weak and slightly evil.
This is a week dogged by death as we have had two fat rats nibbling on our chicken feed - they soon will have to die as they have been chewing on the hens and stealing eggs. Having been in conflict with this species before I am aware that it is not going to be easy and no doubt horrific. How I am going to do it I don't know - any ideas?