Soon winter will come or it might be spring with many cold and rainy wet days. If you're a bee living inside a hive with your brothers and sisters you snuggle with each other on cold days to keep warm.
[See the reddish brown coloured stuff on the edge of the frame at left - that's propolis]
Beekeepers call snuggling "clustering". The bees gather together in a clump and they shiver their wing muscles. This creates heat to keep each other warm. Their beeswax also absorbs the heat from the bees and this warms the hive too.
Have you ever put your hand on a rock at night after a sunny day or the bricks of your house? Often you'll find the rock or the bricks are still warm. They've absorbed the heat. Beeswax works like that too.
[This is a peanut butter coloured clump of propolis I collected from a hive]
Sometimes the wind or rain will come inside the hive through the cracks between the wooden boxes. Or if they are wild bees living in a hollow tree there might be a crack in the hollow that lets the rain and snow in. We know that bees are pretty smart and they do have a way to solve this problem of rain or cold drafts coming in.
How do they do it? They fill in the cracks in their home. People do that too to keep their heat inside. Often they'll use that pink insulation or a white stuff called caulking. They'll squeeze it from a tube into the area around windows and doors. It helps to keep the house waterproof and warm.
Bees use caulking too. Theirs is made by nature. It's called propolis. You say it like this: pro-pol-lis.
Propolis is a sticky sap that the bees collect from the buds of trees. The bee scrapes it off with her mandibles and then attaches it to her pollen baskets. Once she has a load she'll return to her hive and go to the construction area of the hive.
The construction bees will take the propolis and mix it with their spit and a bit of beeswax. Then they'll take it and stuff it into the cracks and holes in their hive. It works like a glue to hold things together and it's also waterproof so it'll keep the rain outside.
[See the propolis mixed with wax pictured on the left side of this frame of honeycomb]
Bees really love to use propolis to glue down the frames of honeycomb in their hive. I suppose they'd prefer if the beekeeper didn't remove the frames ever but the beekeeper will need to take the frames out on occasion to check on the health of the bees and to gather honey. The bees will re-glue things back down again once the frames are put back in.
If you know bees are smart then you'll really want to learn one other really cool thing they can do with propolis. They can make Mummies.