Clever Queen Bumble Bees | Sir David Attenborough's Life in the Undergrowth | BBC Studios

Bumblebees have particularly large and heavy bodies and flight for them can be a real effort. That's particularly so in spring when the mornings are cold and queen bumblebees are just emerging from their winter sleep. It's only a few degrees above freezing but a queen needs to get started early to look for food. The thick furry hairs on her body help to conserve what heat she manages to generate. At the moment she's only a few degrees warmer than the surrounding vegetation as the thermal camera clearly shows. Her body is only marginally more pink than the blue leaves and moss around her. But she has a special way of warming up for flight. She can put her wings out of gear so that without moving them she can rev up the wing muscles inside and that raises the temperature within her thorax by 20 degrees centigrade or even more as the expanding yellow image on the thermal camera indicates. Her body temperature is now over 30 degrees centigrade. At last she has a chance of liftoff. She will now be able to visit the spring flowers while it's still too cold for others to do so. The long trumpets of the daffodils retain heat very well and they're still warm even after their hot-bodied visitors have left.