The other day I went to get Preston in the morning out of his crib. When I walked in I was shocked to find him sitting up playing. I knew it was time to take the bumpers off so I did. This morning I went in to get him and he was sitting up, and trying to pull himself up on the crib railings. So I guess it's time to lower the crib mattress as well. Preston's 7th month sure is a big one for him.