as I left DS3 on his changing mat downstairs while I put DS1 and DS2 to bed - he's been having on of his "I won't drink my milk until I'm screaming for it" days (as opposed to me knowing roughly when he's ready for one and him drinking before tears).
Anyhow, left him watching TV and came on here for a few minutes. Heard him starting to whinge and thought to myself, right lets get down and see if he'll drink his milk yet. Then I thought "his crying sounds muffled - like when he's pulled the bib over his face" so raced down.......only to find him and realise no it wasn't his bib (he didn't have on one)........instead he was lying face down on the carpet at a 90 degree angle from his changing mat............he's finally mastered the rolling onto his tummy