Jan,

My DD crawls on tiles and before she mastered it she was constantly bumping her head/chin/mouth on them. I tried to keep her on her foam mats, but she just got frustrated and would whinge, so I jsut let her go. She was fine and with in a few weeks the bumps to the head lessened. Now she's got bruises all over her legs and knees now that she's mobile though I think it's just par for the course!