Why can you not open a hive when it's cold?

Grid · April 01, 2011, 10:13:34 AM

I have read that we should not open a hive when it's cold, or if it is around the freezing mark, then not to open the hive for more than a minute and then not in direct sunlight.
I have also read that "it's not the cold that kills the bees, it's the moisture", or words to that effect.

If it's NOT the cold that kills the bees, then why should we not open a hive when it's cold? And why not in direct sunlight? Does it have more to do with chilling the brood or disturbing the cluster?

Just trying to learn. I follow both of the above rules, but I prefer to do things because I understand what I'm doing, not just because "that's how it's done". :)

Grid.

FRAMEshift · April 01, 2011, 10:27:28 AM

Quote from: Grid on April 01, 2011, 10:13:34 AM
Does it have more to do with chilling the brood or disturbing the cluster?

It's about both. Chilling brood is a big problem if the cluster is not in place. And individual bees outside the cluster won't survive the cold. If it's cold enough for a cluster you should not be opening the hive at all.

Cold does not kill bees if they have stores and are in a cluster. But you don't want to do anything to disturb that cluster.

Grid · April 01, 2011, 10:39:50 AM

So what temperature is "cold enough for a cluster"? Anything at/below freezing?

Grid · April 01, 2011, 11:00:55 AM

Google is our friend:

"As long as the temperature outside the hive is higher than 64º (18C), bees in the hive are dispersed within it. Come winter, however, the honey bees crowd tightly together in a cluster. The cluster expands and contracts as the weather warms and cools. The winter cluster is a well-defined cluster of bees that forms in the hive when the air temperature dips below 54-57° (12-14C)"

That is a lot warmer than I expected.

I guess don't open the hive for serious inspection if the temp is below 12C (54F), and if needed for feeding, open only the lid outside of direct sunlight for less than a minute.

Grid

Kathyp · April 01, 2011, 11:34:17 AM

that is somewhat area dependent. if you and i wait for those temps to check our hives, it will be July :-). when they fly, you can check. i try to keep it above 50. today i will do my first deep check. we expect to the be close to 60 and, most important, NO RAIN!!!!! :-D

FRAMEshift · April 01, 2011, 11:47:05 AM

Quote from: kathyp on April 01, 2011, 11:34:17 AM
when they fly, you can check. i try to keep it above 50.

Yes, this is the best advice.

danno · April 01, 2011, 01:18:44 PM

Like Kathy said "if you and I wait for temps like that it would be July" I wait for sunny WINDLESS days and open quickly to check the cluster position and to feed. If the cluster is at the top under the cover they can and often do starve in a heavy honey filled hive. Sometimes up here the temps could be a cold as the mid 30's. I open and close very quickly by having everything ready that I will need sitting on top of the next hive. Things like fondant slabs, news paper and a bag of dry sugar and a spacer.

BlueBee · April 01, 2011, 03:29:39 PM

Grid, I think this is a great question! I agree with the consensus that it is not a good idea to open a hive under say 45F, but I'm not sure the physics would agree with the soundness of that logic.

Many beeks will claim that "bees don't heat the hive, they only heat the cluster". If that is case (and the math tends to agree with that myth) then how does opening the hive really change anything? Cold is cold. Now if there is wind, that would be another issue, since wind will blow heat from the cluster.

As for killing brood, again, that logic doesn't hold up to the physics. Brood will die if there are no heater bees around them, or the heater bees contract into a tighter ball. But if cold in = cold out, then there would be no need to contract.

Pulling frames in the cold is another issue. That will break up the cluster, knocking out their heat source and likely kill the hive. However, just popping the lid to take a look doesn't appear like it should cause a big temperature change to the bees at all.

A lone bee on a cold surface quickly dies and hence maybe some of the logic behind this old wives tale is based on the concern of some bees flying out when they see the sun and then quickly dying in the cold.

Never the less, I do hedge my bets here and don't fool with my bees if it's below 40F ;)

iddee · April 01, 2011, 03:39:16 PM

I was taught the bees begin to fly at 43 F. Below that, they are fully clustered. From 43 to 55, they are in semi cluster. I have nothing to back it up, but I have found it to be a fairly good guideline.

VolunteerK9 · April 01, 2011, 03:51:25 PM

Quote from: FRAMEshift on April 01, 2011, 11:47:05 AM
Quote from: kathyp on April 01, 2011, 11:34:17 AM
when they fly, you can check. i try to keep it above 50.

Yes, this is the best advice.

Same here, if they're not flying, I'm not looking

Brian D. Bray · April 03, 2011, 01:34:41 AM

The "if they can fly the hive can be opened" is probably the best advice. But at what temps they will fly at vary greatly around the USA depending on highs and lows of summer and winter temperatures.
I've seen bees fly with temps as low as 33 F (Russian) but I wouldn't open the hive then. If they're flying between 45-50 degrees outside temps it would be okay to check the hive, but bear in mind that the cooler the temperature the testier the bees.
Other factors that contribute to a successful hive inspection are sunny days, little to no wind, and adequate smoke.