Bumps in the Night!! Oh MY!!

I have a reputation for being a sleepwalker and a sleep talker. Since I was a child, I have done odd nighttime things, and don't usually remember any of it.
As a newly married wife, it has been a little embarrassing for me, as my husband discovered this tendency in me over the last year and a half.
So far there has been the mystery of the cat food in the toilet, unlocked doors in the mornings that were securely locked at night, and odd midnight mutterings.

Fast forward to last night. Our cat, Splat, usually sleeps with us in our room; either in the bed under the covers, or on her own chair on the other side of the room. Whatever she prefers. Last night, we went to bed in our room as usual, and she decided to sleep on a huge pile of ruffly dresses and frilly things I've been sorting through in the guest room across the hall. Ok, fine; whatever she wants to do.

Around 4:45 am, I was suddenly awakened by thumping and bumping on our bedroom floor. And muffled squeaky noises. This could NOT be Splat; she is a tip-toe ing kitty and walks with far more grace. Something was wrong! I sat straight up in the bed and looked down..... to see a dark shape fumble under the bed out of sight. I flipped over and shook Kevin.
"KEVIN! KEVIN! there is something in this room and it is not Splat! She is in the guest room! Something is in here!"
"Whhhaaaaa......?"
I saw the shape again.
"It's a possum! There is a possum in the room..... look! It went under the bed!"
I retreated to the middle of the bed, where it couldn't get me. I was seriously terrified at this point. I mean, I am ok with rodents outside, but if they're up in the house, and might jump on my bed, I am terrified of them.
By this time, Kevin was hitting the sides of the bed, trying to get it to come out. He went to get up and flip the light switch on, and I held him back.
"NO! It'll BITE you!"
At that moment I saw Splat out of the corner of my eye, on the other side of the bed.
"OH, LOOK! There's Splat! She's going to try to chase it..... come up here, Splat! Get away from it!"
I was truly panicked about it. I mean, I was afraid it was going to bite all of us.
Kevin jumped off the bed and hit the light switch and.................................
 
"It's a MOUSE!Look, right there. It's just a mouse."
The shape I saw was indeed our cat, in crouch and attack mode. THAT's why she was thumping and fumbling all over the floor, unlike herself. And the squeaks? Uh, yeah.
We let her keep it and play with it; we encourage our cats to enjoy catching rodents. I have NO idea why I thought a possum would be in the house; I guess I have a subconscious fear of things coming down the chimneys; and I'm not talking about Jolly old St. Nick, either.
This morning, as I pulled out of the driveway to go to work, Kevin says:

"Watch your speed. And watch out for possums......"