Recently we've been splitting what we can. Today we went through hives that needed attention. The trends that I saw were: lots of polished empty cells, no eggs, lots of queen cells in various states (capped, chewed, open) and some older capped brood with nectar, pollen and a little capped honey. We saw one unmarked queen wandering around and did not mark her because she was not laying eggs...probably newly emerged and unmated. Here's a queen coming out of her cell!
Due to the strange Spring temperature variations, there were lots of swarms so far this year. It's been difficult to get in the hives. There was a huge swarm 30 feet up in a tree at the barn and one smaller one forming on the hill.
This time of year it's OK to add foundation. The bees are in the mood to draw it out and it may occupy them a while so they are less inclined to swarm.