Septic tank’s never complained!
Never happened often, but occasionally I’d wake up to the odd thumping from the other side of the bedroom wall - bathtub playpen would be hosting a cat vs. mouse MMA match. Really cute how she learned to keep the dogs from interfering as they would have (and did) on open floor.
As I was living in my house, finishing the trim work, my two cat boys caught a rat and took it up to the step landing where the stairs turn 90 degrees then ascend further. They kept the poor thing trapped on the landing until it died. I found the blood scene and the rat, headless of course. Their favorite was to catch a young rabbit and trap it on the front porch while they mauled it repeatedly. I’ve put more than one BB in their butts for making me have to put a mangled rabbit out of its misery. Both of those guys are gone now ... and I miss them so much.