Other things to look for:
- curiosity about nest boxes. If you use nest box bedding, not just nest pads, you might see them digging away. My EE built little nests around herself of the hemp bedding before she started laying. Playing house, I think.
- lots more vocalization and restlessness
If you haven’t already, start providing oyster shell now. My girls prefer flaked (available on Amazon) to the more common chunks. You can leave them on chick or all-flock feed, which is generally higher protein, as long as you provide shell.