Isaiah is crawling and talking

Isaiah started saying "dada" several weeks ago. We doubted he really understood it until about two weeks ago when he began only using it when talking to me. Then he added "mama" and "baba." He babbles constantly now and plays with toys on the floor. He does the same sidewinder army crawl that Gabe did, but he is showing signs of getting on his knees to crawl soon. He is eating cereal everyday and likes it now. For some reason he has been crying a lot lately and sleeping less. Hopefully it is teething that is bothering him. Hopefully it ends soon.