Teagan went from sitting and occasionally getting down her belly and screaming to full on terrorizing the house with her mobility over night. Seriously, two days ago, I could plop her down, leave the room for a minute, and she'd be in the same spot when I got back. Yesterday, I watched the mobility switch flip. Literally, she was on her belly doing her thing and suddenly started moving forward with some speed! Life as we know it has changed. At least she's far less frustrated now. OK, off to do some baby proofing!