We also discovered that they are now able to jump onto the edge of the brooder (kiddie pool - it stands about 15 inches tall), so my husband added a new level of height all around their little home. That should keep them contained for a little bit longer anyway.
I also think that my little chicken that I thought was a Silver Sebright, may actually be a Silver Speckled Hamburg Chicken, now that the feathers on the wings are starting to come in nicely. Who knows, I guess only time will tell for sure. Goodnight All!