I'd say the same thing whether it was a rat, ferret, dog or cow.
Can't help you with the cow part... see the slaughterhouse old threads on here...
Not sure where you're going with this, nobody likes cruelty to animals or anything living. Some people refuse to step on a spider or even an ant. I go out of my way to save ladybugs flying around the house from time to time, or if I happen to be in a good mood, I'll catch a wandering spider and free it outside. If my kid is around and sees it and freaks, it gets the foot. Or if an ant happens to have balls and climb up my arm or leg, it's toast. I show no mercy to anything stupid enough to piss me off. That goes for mice coming into my house or any intruders.
When you have a bee or wasp flying in your house, do you go to painstaking lengths to capture it and set it free or do you grab the bug spray? If you try and save it's life, I can honestly respect that as a code of yours, it's cool. But you can't bitch out the guy who swats it, either.
I guess your point is not to have any creature endure a horrible death, which I understand... bug spray is certainly not a fun way to die. But when the bee is hanging out of reach, what choices do you have?
Not all traps are created equal. I personally don't like the snap traps, nailed my fingers once too many times, and it's dangerous to leave them around with kids in the house, so you won't convince me to go your route on this one, good effort tho buddy!