Stella can turn off a tantrum with a moment's notice if something interesting happens. If we suddenly notice there's a package on the porch, if someone rings the doorbell, if a firecracker goes off nearby -- the fact that something more interesting has happened often means she turns off the screams immediately and gets happy. So we often try to manufacture events to distract her during tantrums. "Wow, Stella, look, there's....uh....a...a...a really WHITE plane in the sky. That's the WHITEST plane I've ever seen!" If the world has to end in my lifetime, I hope it at least ends during one of Stella's tantrums; it would cheer her right up.
The cats catching a bird in the basement definitely qualified as an interesting event and Stella stopped her tantrum to investigate. In the 12 years we've lived in this house, this is the first time we have had any wild animals make their way inside. My sister, who owns a house of a similar age about a mile away, has a bat population in her attic to the point where she has guano deposits up there. It would almost be worth having bats if it afforded you the opportunity to say "guano" a lot. Weren't there wars fought over that stuff back in the 1800s? She's got white (or whatever color bat poop is) gold, right in her attic.
Bats in the attic and walls are one thing, but invariably one squeezes out and then you've got a flier in your bedroom in the middle of the night. One time she opened up the washing machine and there was a bat inside the lid hanging upside down which just is not a good image. True, we've never had a bat in our house but I should probably avoid doing laundry just to be on the safe side.
Also on the topic of animals where they shouldn't be: David once told me a story of how when he was a kid, his sisters played with an old baby carriage that was kept in the garage. One day they went to play with the baby carriage and there was a possum curled up in it, playing dead. Somebody went and got the neighbor who shot and killed the possum while it was still in the baby carriage. Wow. (If I ever write a short story, it's going to be called The Possum in the Baby Carriage and the possum will symbolize, you know, the death of America's post-war dominance and the neighbor will symbolize the Viet Cong.) I am not necessarily suggesting shooting the bats but you have to agree the idea has potential.
Our cats were going batshit (get it? BATSHIT!) trying to catch the bird, which to be honest surprised me since these cats are severely lazy. I thought they didn't pay attention to anything unless it came out of a bag and went crunch crunch. In the end, I opened the door to the outside and when I returned a few hours later the bird seemed to be gone. I'm glad I didn't have to escalate by calling in the neighbor; still, I'll miss the guano.