Okay I must say im a little disturbed.. You don't want to be cruel, but you are willing, and have before, drowned the predator? I'm sorry but that is cruel, just as cruel as a pitchfork / baseball bat.. And to the person who suggested a hose with car fumes? Also, JUST as cruel.. Since you can't shoot it because of where you are located, then If you do ever get the thing in a trap, then just kill it FAST with an axe or hatchet :S That isn't cruel, well I mean any way of killing an animal is cruel.. but atleast its fast, they don't suffer AT ALL, they will die instantly and if you want, do it over your shower curtain so you have no mess to clean up -.-
.. I hope you know that drowning them, which is what seems like you have been doing, is most definitely cruel and you put that animal through quite a bit of suffering when you do that.
I'm on your side and understand you want your ducks and chickens to be safe, as I would too, I do everything I can to keep my pets out of harm, but you can do it in a humane way, and please think about that when trying to get rid of your predators.
Seriously. Trap / Relocate yourself, or Trap & Hatchet / axe, or poison or shoot.
No pitchfork No drowning No car fumes No mutilating No baseball bat..
Thanks and hope you can get rid of your predator and save your kitty & other aminals<3