A mouseguard is a strip of galvanised metal, punctuated with 10mm circular holes which are ample for a bee (even with good saddlebags of pollen!) to enter the hive, but which exclude even the most sinuous mouse. Here’s one on the entrance of Thames Hive.
It is crucial to put these mouseguards onto the hive entrance before the first frost of the year, or risk an invasion of bewhiskered rodents. If a mouse, or a mouse-family, is driven by cold and famine to seek refuge and sustenance in a drowsy, clustered, wintry bee-hive, the results are disastrous. The mice will ravage the honeycomb, depriving the bees of their hard-won bounty.
So in the first place, mouseguards on as soon as the weather threatens to tip towards winter is a sensible precaution. If a beekeeper suspects that mice may already have invaded the honeyed Elysium of a hive, lore has it that a sharp whack with the flat of his hand at the back base of the hive will send the free-loading mammals rocketing out of the hive entrance. If a mouse happens to expire in the hive, the bees have no way of removing its decaying corpse, so they encase the mouse-body, mummy-like, in a cocoon of propolis.
But rules are there to be broken. The weather forecast is set fair for a fortnight, with temperatures way above freezing. Yet I have put mouseguards on my Bermondsey hives already. My reasoning is that this has been a great year for flora and fauna alike. So there will, presumably, be a lot of mice around. In such prolific numbers, they may be forced to seek out a sustainable supply of food for their numerous offspring well before the classic frost-signal is sent to beekeepers.
Here in the Bermondsey Street hives, at least, there’ll be “Nae Moose Loose Aboot This Hoose“.