Liam was leap frogging at around seven months, rocking on his hands and knees and then just take off leaping forward. I was so scared he was going to injure himself. He started using his knees last week. He is exploring every open space and getting into mischief. You think you have babyproofed your house then....

Prior to this from six months on, he was rolling all around the floor, exploring a pretty big space in my living rooms.