Cats are Ridiculous

I'm currently sitting on my bed in my parent's house doing stuff on my computer.  My brother's cat is sitting at the end of the bed just chillin'.  For no apparent reason, the cat starts to make squeaking sounds.  Seriously, what is wrong with this cat?  When I look down at her, I realize she is staring intently out the window.  I assume that she must have spotted a bird or bug outside the window.  For the next several minutes she continues to squeak and get more and more agitated until she begins to slowly and stealthily crawl towards the window.  I watch in anticipation wondering what she will do when she gets to the window.  She crawls to the very edge of the bed, curls up a bit like she is going to jump, and then walks onto the window ledge..I was a little sad she didn't try to jump through the glass and give me a good laugh, but I'm still curious what she is after.  She gets into the window and starts pawing at the window.  I realize that there is a mark on the window there...she must have thought she was going after a bug that turned out to be only a mark.  After a few bats at the mark on the window she realized it wasn't going to move and gave up.  Guess I got my laugh anyway. :)