I was four years old, the summer Neil Armstrong landed on the moon. Pretty smart for a four-year-old, really, to have figured out that much stuff without having ever been to school. They were dying. A feral farm cat had torn up the mouse, and the sparrow had hit a window and broken its back. I couldn't just sit there and watch them die without trying to do anything for them, so I did what I thought might help. I guess I probably should have just snapped their necks (mouse's neck might already have been broken by the cat, dunno). That would have ended their pain, but I wasn't *that* smart. Still, I think the water sped them on their way, so in that way, they probably suffered a little less.
You must mostly be cityfolk. I'm cityfolk too, now, but I grew up rural, so I'm not squeamish about stuff. We killed and ate a lot of different animals. I remember when I was three, my dad took me out back with a small axe. He got a chicken and showed me how to hold its head on a stump, then handed me the axe and told me to chop its head off, because that was our dinner. Well, I wanted to please, so I chopped it off, clean, one stroke. But what happened NEXT totally freaked me out. The headless chicken ran forward about ten feet, convulsing and squirting blood out of its neck, spun around in a circle twice, then collapsed to the ground, pulsed out a couple more jets of blood, then FINALLY died. Now *that* was gruesome. But...you do get used to it. It's natural; we're at the top of the food chain, and if you can't face the reality of where that grocery store meat comes from, you probably shouldn't be eating it.