Description
Photo of a large earth bumblebee (Bombus terrestris) on the flowers of Aconitum lamarckii
Note the "bite hole" through which the nectar source is accessed. I spent an hour observing and photographing different bumblebee species on our aconite plants, amongst others to finally document this behavior (also called nectar robbing). Almost all the older flowers on this aconite plant show these bite holes, partly frayed from being visited so often. The bees did not carry pollen, so I assume they were only out for the remaining nectar, visiting the flowers over and over for food. They were also unimpressed by approaching rain, which may be a hint that they were starving and rather risked getting wet than leaving precious nectar remnants to competitors.
More of my "flower devils" here wiebkerost.com/flower-devils/