Top Reddit comment:

But even though the same neurochemicals are involved, it’s a step too far to say that bees experience happiness in the same way that humans do, he adds. “It’s hard to know if or what bees could possibly think,” he says.

To bee or not to bee, that is the question.

More:

https://newscientist.com/article/2107546-dont-worry-bee-happy-bees-found-to-have-emotions-and-moods

https://reddit.com/r/science/comments/558bi4/dont_worry_bee_happy_bees_found_to_have_emotions/

If bees feel happiness, do they feel optimism?

http://www.sciencemag.org/news/2016/09/don-t-worry-bees-are-happy

Study: Unexpected rewards induce dopamine-dependent positive emotion–like state changes in bumblebees

Abstract:

Whether invertebrates exhibit positive emotion–like states and what mechanisms underlie such states remain poorly understood. We demonstrate that bumblebees exhibit dopamine-dependent positive emotion–like states across behavioral contexts. After training with one rewarding and one unrewarding cue, bees that received pretest sucrose responded in a positive manner toward ambiguous cues. In a second experiment, pretest consumption of sucrose solution resulted in a shorter time to reinitiate foraging after a simulated predator attack. These behavioral changes were abolished with topical application of the dopamine antagonist fluphenazine. Further experiments established that pretest sucrose does not simply cause bees to become more exploratory. Our findings present a new opportunity for understanding the fundamental neural elements of emotions and may alter the view of how emotion states affect decision-making in animals.

A bee enters a cylinder with an ambiguous reward in the study of bee "feelings." CreditClint J. Perry

So bees feel but it's not quite like human feelings.