I feel guilty at killing anything tbh, I use live river shrimp, crickets, locust, earth worms and meal worms all occasionally..
I once saved some goldfish I added to my giant snakehead tank a few years back, some bitten in half but living got fed to the African pike, that made me feel pretty bad.
My mantis is pretty darn cruel to the crickets eating them alive eek.
I had an African bullfrog and that was making me feel like Hitler.
He would eat 5 boxes a week!
All my fish will take dead and most take pellets, I like to imagine all the frozen was killed humanely.
They are all living creatures, I keep 2 snakes aswell, both eat ft rats, it's actually illegal in the UK to sell any fish or mammals as live food.
I understand some fish and animals won't take dead food, I still believe every effort should be made to convert them.
I have no issue shooting a rabbit as long as I'm gonna eat it, I wouldn't kill for fun... Imo that's just wrong as is enjoying watching an animal suffer as it gets devoured... Gotta have a screw loose if you enjoy it imho. I do feel the small critters I feed are beneficial to my pets tho, that outweighs the bad feeling somewhat.
I quite often let the last couple of crickets in a box go free lol, sound like a right pussy I know!-)