Yes, you really do want to build an observation hive.

In this first picture, you can see a chubby yellow drone, newly hatched, center top.  You can also see the ladies warming the remaining drone cells by pressing their thoraxes against them, bottom right & just left of center bottom.  Most drones from the brood I placed into the OH have hatched now.

The beautiful weather has returned, and all of the blossoms that have been on hold during the chilly weeks are out there awaiting the bees.  The bees have had no problems navigating their tube.  I have it exiting through a hole in a 2x4, which is set in the window, rather than drilling holes through my walls like real die-hard bee-zerkers would do.  :)  It is rewarding to see the heavy loads of pollen and nectar coming in. The comb is glistening with cells full of golden liquid, and others packed with bee bread.

There is an opening into the tube in the middle of that crowd.