Why does my dog constantly smell bees?

I've found an odd trait my dog has developed. For some reason she literally can find those big black and yellow bumblebees out of nowhere. Then she will just sit there and smell the bee non stop. When she's smelling it, her lips curl up and start quivering, and she just keeps doing it and doing it and doing it. She doesnt try to eat them she just smells them over and over again. Will sit there and smell, lip starts quivering, smell again, lip quivers, etc. Why is she doing this and is there some sort of pheromone that bumblebees release that is making her enjoy smelling them? Like is it some sort of good, calming smell that she loves or what? I'm thinking she's just a really special dog and not normal lol. But the whole lip quivering thing tells me she's smelling something that is like turning her on or that she's enjoying.