Serendipitously, we were witness to a bumblebee queen mating in our garden.
Not knowing much about bumblebees, we were quite surprised. Most other bee species mate earlier in the year. Honeybee queens do it in flight, so you never actually see the deed. Mason bees and other solitary bees also mate shortly after emerging in the spring. By contrast, bumblebee queens mate late in the year and then hibernate by themselves, producing a new hive the following spring. Hopefully this queen will find a safe place in our garden and survive the winter.