Because it's there.

And so it begins...

This is bunny history in the making--the discovery of how to climb stairs.

What a rush!  New mission--climb all the stairs!!!

Don't leave meee!
This is how Simon got "peer pressured" into climbing the stairs.

The bunnies have reached the second landing and decide to make base camp here in order to adjust to this massive change in altitude.  Simon seems distinctly less happy than River at the prospect of climbing more stairs.

At this point, Simon is beginning to wonder what exactly he's gotten himself into.  River seems to be egging him on from the second floor.  The look she's giving him screams, "Follow me you pansy!"

A close-up of Simon's look of regret.

Simon finally makes it up to the second floor and does a bit of exploring.  He looks like he's saying, "Oh, fantastic!  Two closed doors and a floor I can't walk on--that was really worth the effort.  Thanks for making me follow you on this grand adventure, River." 

Wait, wait, wait!  You're not just gonna leave me up here, are you?!  How do I get back down?!?!
...And she's gone.

Oh, what was I thinking following her up here?!  Okay, don't panic...

I know!  I'll just act like I meant to get stuck on the second floor for the rest of my natural life.  Yep, no regrets here!
At this point, I had to carry Simon back down the stairs.  On the way down, he made the mistake of looking at how far up off of the ground he was.  He made an "Eeeep!" sound and promptly proceeded to bury his little face in my cleavage until we were safely on terra firma.
I told him that if he went upstairs again, he'd have to figure out how to get back down on his own.  This, my darlings, is the subject of tomorrow's post.