I think that these Bumblebees may have been from the same nest because they weren't trying to push each other off of the flower.
Tech Specs: Canon 70D (F11, 1/125, ISO 200) + a Canon EF-S 60mm macro lens with 25mm of extension + a diffused MT-24EX (flash head "A" set as the key and "B" as the fill). This is a single, uncropped, frame taken hand held.
Technique: I cut a Zucchini flower, taped it upside down to a leaf, and then injected artificial nectar into it. I used the flash to expose the subjects and natural light to expose the background.