Sam says "Dada!"

Sam made "d" sounds for the first time today! He was mimicking me- when I said "dada" he said "da" and a few times said "dada." I don't think he knows Andrew is "dada" but it was really exciting to hear him purposely imitating me! He's changed so much in the last few days, first pulling himself to his feet (he continued to do so today and took a fair number of tumbles) and now saying "da"!