When does baby start crawling?
There is a wide range in terms of when babies reach this development milestone. At 6 months old, they may start to rock back and forth on hands and knees, and by 9 months, they start to creep and crawl. However, each baby has their own timelines, and it's not uncommon to see babies skip crawling all together.
Instruction: When does baby start crawling?
Context: 
Response: There is a wide range in terms of when babies reach this development milestone. At 6 months old, they may start to rock back and forth on hands and knees, and by 9 months, they start to creep and crawl. However, each baby has their own timelines, and it's not uncommon to see babies skip crawling all together.