Get ready to baby proof your home. "By nine months of age, some babies start crawling, but many never crawl and go straight to walking," Dr. Jacobson admitted. "The baby should be able to sit himself up. The baby also can start saying mama and dada, but not necessarily specific to his mom or dad all the time. The baby also should start having pincer grip so he can pick up a Cheerio with his finger and put it in his mouth. Some 9-month-old babies start clapping, giving high fives, waving bye-bye, and blowing kisses." Aw.