entropy fan
I've been telling people lately that Lijah is opposed to potential energy. If he sees something standing up, he wants to knock it down. And his devotion to chaos and low-energy states also extends to wanting to take things apart; if it were up to him, no two legos would ever stay attached to each other, and any uneaten food would be reduced to the smallest crumbs and scattered all over the ground. And you should see what he does to bookshelves! I don't know if he loves bookshelves or hates them, but in either case he can happily spend a good long time patiently pulling each and every book down to the floor. Ditto for the tupperware cabinet.
So far, he's shown no impulse at all towards building. Maybe he figures his brothers have that under control; they certainly spend plenty of time on it (ideally in safe places like high tables or on another floor from the little agent of destruction). As parents we have mixed feelings. On the one hand, the mess! On the other, when provided with enough things to take down or out Lijah can amuse himself for a good long time, which is more than we could say for Harvey or Zion at this age. If you move quick you can even get some cleaning done in one part of the house while he wrecks up another: since we move slightly faster than he does, with constant work the net effect is—very slowly—a cleaner house.
And of course, whenever you want to get his attention all you need to do is set a single block up on edge, and he crawls right over: he's not going to let that stand for long!