We used to have cats... found a dead squirrel tucked into a hole in my son's comforter. Thankfully he was going through a phase of refusing to sleep in his own bed at the time.
Same kid was traumatized by a chipmunk hiding in his shoe at a very young age - it jumped out at just the right moment to give me a heart attack, I screamed and scared him silly. He spent the next 3 months asking about "munks inna shoe" and "munk unna my bed?"
Finally, there was the slaughter incident. Same (poor) kid and I got home with just enough time to grab a snack and change before soccer practice. I made him a sandwich and sat him at the kitchen table then went down the hallway to get his practice stuff. Notice a drop of something on the white tile, then another, then another, by the time I got to the end of the hallway and into our bedroom, it looked like something out of a horror movie. Did a quick search and couldn't find the victim. Threw the kid in the car, called DH and told him what happened and to clean it up/find the victim when he got home - he decided then and there he had to work late. Weird thing, even after tearing the house apart later that night, we never did find out what it was.
After the last incident, we closed up the cat door. If they wanted to go outside, they had to be cleared before being let back in.