Not really the knees, but filled pollen baskets. That’s what stopped me in my tracks inside the Presidential gardens. As I tried to take a better picture, a plainclothes security man appeared at my elbow and said “You can’t stop to take pictures.” Without taking my eyes off the bee, I said “But photography with the phone is allowed in the garden.” He replied “But it doesn’t mean that you have to take a photo of every flower.” I conceded that point, but argued that I hadn’t, I wasn’t even so interested in the flower. It was the bee I was looking at. But he didn’t stay to listen to me; other knots of people attracted his interest.
Bees do not feed on nectar alone. While carbs are good for giving them energy, all individuals, especially the growing larvae, need proteins and fats. That comes from pollen. Bees are not being altruistic in taking pollen from one flower to another in order to further the reproductive success of plants. They harvest pollen, and nectar, in order to feed themselves. The sexual favours to plants are incidental. Hairy species of bees just carry the pollen in mats of hair called scopa. But these red dwarf honey bees (Apis florea) have pollen baskets, corbicula, on the tibia of their hind legs instead. I haven’t noticed them so full before. I wish I had panniers built into my legs; it would be a very useful alternative to plastic shopping bags.
Don't hold your breath 