“Cracking the hive” is a simple, rapid way to check your colonies for queen cups and elongated queen cells that could indicate an imminent swarm. Use this quick inspection method to determine whether a hive is congested and swarm-prevention measures should be taken.
Instead of removing the inner cover and individual frames, just remove the outer cover, leaving the inner cover in place. Or, if there are honey supers, remove them as well.
Separate two remaining hive boxes: pull the top box back 2 to 3 inches, and with a quick lifting motion, tip the upper box forward and upward at least 45ᵒ and be confident that it will not slip off.
Examine the top bars of the lower hive box and the bottom bars of the frames in the upper box, rapidly scanning for queen cups or enlarged queen cells on bottom bars. If there are very few queen cups and only some of them are enlarged, the colony is not yet too congested.
Be quick! Especially in the chill of an early spring season, you need to make your observations and assess what is taking place within 5 seconds.
To finish, lay the top box back onto the bottom box and smoke the 2- to 3-inch gap to get the bees off. Then slide the box forward to close the hive.
This method can be applied at any time of the active beekeeping-year to check for queen cups and swarm cells, but only if you have wooden boxes, rather than plastic. It is especially useful when time is short or hives are many.