When to Reduce Your Hive Entrance (and When to Open It Back Up)
The entrance reducer is the cheapest piece of equipment in the beeyard and the one most often left in the wrong position. Too open in September and you invite a robbing frenzy. Too closed in July and you cook a strong colony. Here is the whole calendar in one page.
The short version
Reduce for anything small or vulnerable: new packages, nucs, swarms, and any colony going into a dearth. Open up for a strong colony during a flow. Reduce again in fall before the first cold nights, and leave it reduced through winter with the top vented. The rule underneath all of it: a colony should only have as much door as it can guard.
Spring: a new colony needs a small door
A package or a nuc has a few thousand bees trying to defend a box built for sixty thousand. Give it a wide entrance and every wasp, robber and beetle in the neighbourhood walks in unchallenged. Reduce it to an inch or two of opening until the colony has drawn most of its comb and the front of the hive is busy.
The tell that it is time to open up is traffic. When bees are queuing on the landing board and bearding around a choked entrance on a warm afternoon, they are telling you the door is too small.
Summer: open it, but watch the dearth
A strong colony in a nectar flow needs to move a great deal of air and a great many foragers. Open the entrance fully. A restricted entrance in July costs you honey, because bees that are queuing are not flying, and because the colony is spending energy fanning that it should be spending on the flow.
Then the flow ends. In most of the country that is late July into August, and it is the single most dangerous moment in the beekeeping year for a weak hive. Nectar dries up, foragers start looking for an easier source, and a colony that cannot defend its door gets stripped in an afternoon. When the flow breaks, reduce every colony that is not visibly strong.
Robbing looks different from foraging. Robbers fly a wobbling, searching pattern at the front of the hive rather than a straight in-and-out. They fight on the landing board. They are shiny and black where the hair has been rubbed off them from scrapping. If you see that, reduce the entrance to a single bee-width immediately and consider throwing a wet sheet over the hive for a day.
Fall: reduce before the mice do it for you
Two things happen in autumn. Robbing pressure stays high through the dearth, and mice start looking for somewhere warm and dry with a food supply. A mouse in a hive over winter is a disaster: they nest in the comb, chew through frames, and the colony cannot evict them once the cluster forms.
The timing is easier than people make it. Mice move in when the nights get cold, so reduce the entrance around the time you stop needing a jacket in the evening and well before your first hard frost. If you wait until the cluster has formed you may be shutting a mouse in rather than out.
Fall is also when you should be doing your most important mite work, and the two jobs go together. Your last treatment of the year wants to land on the last warm day, and you are already at the hive at that point — reduce the entrance while you are there.
Winter: small door, open roof
Leave the entrance reduced all winter. The colony is not foraging and the only traffic is cleansing flights on warm days and the occasional undertaker bee.
What matters much more in winter is what happens above the cluster. Bees survive cold; they do not survive being rained on by their own condensation. Warm moist air rises, hits a cold inner cover, and drips back down onto the cluster. Keep an upper vent or a small top entrance open so that moisture can leave, and make sure the reduced bottom entrance does not get blocked by dead bees — on a mild day, clear it with a stick.
A note on closing a hive completely
The only time to shut a colony in entirely is when you are moving it, and then only briefly and with proper ventilation, ideally at night or in cool weather. A closed-up hive in the sun will cook itself in less time than you would think.
What to use
A wooden entrance reducer is what most hives ship with, and it works right up until you take it out in April and never find it again, or a mouse chews through it. We got tired enough of that to start moulding our own.
Lorob Bees Hive Entrance Dials
- It rotates instead of coming out, so there is nothing to lose in the grass. Open for a flow, choked down for a dearth, shut for a move.
- Made in our shop in Maryland with a premium UV additive, because we were sick of dials going chalky and brittle after one season in the sun.
- Seven colours, which is the other reason beekeepers use them — colour-code the yard and you can see from the truck which hive needs attention.
- Fits Apimaye boxes exactly, and works on home-built boxes, nucs and swarm traps. 10-packs and 150-count cases, or a 150 mixed-colour case at a lower price because you cannot choose the shade.
Related reading
- Robbing bees: how to recognise it and stop it
- Winter bees, and why colonies die in January
- How much oxalic acid per hive
- Why did my bees abscond?
Happy Beekeeping from the Lorob Bees Team
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