Here in southern England we have to protect our bee hives against Woodpeckers who occasionally attack colonies usually in late winter when insects are hard to find and other food sources are scarce. They can rip into either a wooden or polystyrene a hive in seconds creating a two inch wide hole through which the woodpecker can make quite a meal from the thousands of bees inside trying to defend the hive. A hole that size is impossible for the remaining bees to close up and usually the whole colony is dead from cold within days.
It seems that only Green Woodpeckers attack hives in certain areas at certain times, and it's thought that it may be where families or groups of birds teach each other how to attack bee hives. It's also interesting how the woodpeckers seem to know exactly where the weakest point is and always attack where the hive material is at its thinnest, usually where the handholds are on the side of the hives.
So to counter this, we have to protect our hives with either chicken wire or in my case plastic mesh fencing. The mesh is big enough to let the bees through, but too small for the woodpeckers, preventing them from getting too close to the hive exterior. We usually fit these at the end of December or early January once we have treated the colonies with oxalic acid to greatly reduce the numbers of Varroa mites attacking the bees. The bamboo poles hold the mesh away from the hive body and can easily be removed, allowing the mesh to be lifted away if we need to inspect the inside of the hive or feed the colony for any reason.
The mesh will stay in place now for the next few months keeping the Bee Good colonies safe and sound until later in the spring when the weather has warmed up and the woodpeckers have plenty of other insect food available...