Kai has now achieved a certain degree of mobility. He can crawl, he can stand, he can shuffle forwards on his butt cheeks. It's not quite the whole package yet, but not to be sniffed at.
This is great news for him - existence is now twice as fun. This is not so good for us because it's difficult to pop out of the room for just a few minutes without him either (a) hunting you down in a Here's Johnny "The Shining" vein or (b) finding something interesting to destroy behind your back. There's no insurance to cover baby-induced incidents like this.