I'm not quite sure if this is intended, but I found that when you drop items on the side of, or on top of a cactus, the item disappears instantly. I know that items have health, and cactus's do damage when collided with entity's, but I think that if it is intended, that it should be removed, my own opinion, but if its intended, that's okay. But if it is a bug, then I think it should be removed.