Girls, tell me how many months old your babies are and how they've bee…

Girls, tell me how many months old your babies are and how they've been crawling? ? And how did it start? My little son started getting into a mermaid pose a couple of days ago, and lifts his bum, pushes off with his feet and crawls. By the way, he doesn't sit and crawl on all fours yet. But calmly gets from point A to point B.