I thought I had a photo of a honey bee's tongue. Found out from the experts that it is actually a mouth part called a galea and it has hair like sensors called palps on it that can detect the concentrations of sucrose, glucose, and fructose. A highly desirable flower would have a high concentration of these in its nectar.
SUNSET / BLOOD FLOWER Scarlet Milkweed (Asclepias Curassavica)
Honey Bee (Apis mellifera)