Propolis - the super glue of bees

When I inspected the hives today, there was lots of propolis . The propolis was sticking the frames to each other or sticking the honey supers to the hive body. It was under the inner cover, sticking the inner cover to the super below. I gathered this glob of propolis on the end of my hive tool.

The propolis in the picture is orange but it could be other colors. How it looks depends on what the bees are gathering. When bees use it to glue parts of the hive together or to fill empty space, beekeepers say that the bees "propolize" the space.

Was it sticky! I imagine getting this on the bottom of your shoe would be much worse than gum, for example. It felt resinous and it rolled into a ball with a smooth exterior.

Bees use propolis for many purposes, including cementing parts of the hive together. They also use it to keep the size of bee space
the same everywhere in the hive