Rolly Polly

My child has turned into a rolly polly this weekend. He has been rolling from tummy to back for awhile now, but this weekend... with a full audience of family members that were here to visit, he decided he would roll from back to tummy.  Now the second you put him on the ground he rolls from back to tummy and then back to his back.  He usually does it really fast too! It is like speed rolling. I am thinking he won't be staying on his play mat very much longer and he will be rolling off of it soon... I have a feeling he is going to be an active child.