He is still at the crawling stage (he stands, and very occasionally takes a step or two, but crawling is still his primary means of transportation). No terrain is too challenging for him – he can crawl up and down stairs, he can climb down from sofas and beds, and I’ve even seen him climbing onto the sofa once or twice. He also climbs out of the front door if you leave it open.
He’s aware that to climb down from something, you need to do it backwards. So he’ll turn round and reverse into position. Sometimes, he gets into reverse a little early. So you’ll see him crawling backwards across the sitting room towards an open front door that’s about twelve feet away. This gives you plenty of time to close the front door, before tousling his hair and saying “You are so *cute!*”
Another cute thing that he will do is to bring me a book, and then climb up onto my knee to read it with me. Rarely do we read the entire book – generally, he cherry-picks a page or two, and then goes off to find another book or do something else entirely.