Standing up!

So now I really like to stand up in my crib when it's time for Mommy to get me out in the morning. Usually, I'm pretty quiet, but if she doesn't come after the first few times I say Ma-Ma, I start to yell a little. Mommy says I must have strong lungs and strong legs! After a while, my legs get tired, and I start to droop and lean on the side a little.