Just the facts about "bee barf"
One of the questions we often hear, especially from kids (and some adults), is, "isn't honey just bee vomit?"
The answer is no. But, it does require a little explanation, and more often than not, people are more than happy to just continue believing the mildly gross myth.
Part of the misconception comes from a simple lack of biological knowledge. If you assume that all animals are built the same as humans, that blanketed biological view sets you up for failure. Many animals have a crop—a holding cell of sorts—in which food is temporarily stored before it enters the central part of the digestive system.
Many birds have a crop where food is stored to be digested later. This allows them to overeat while food is plentiful and digest it at leisure while safely tucked away from danger. It also allows them to ferry food home to the nest; this is very similar to what bees do. Other animals, including slugs, snails, leeches, earthworms, and many types of insects, also have crops.
Other digestive organs are also common in the animal kingdom, such as gizzards, which aid in grinding food, and stomachs with multiple parts, such as those found in ruminants. It pays to remember that humans don't have all the cool tummy bells and whistles—just some.
In insects, the crop is also known as the ingluvies. This is because it occurs before the proventriculus, a valve that marks the beginning of the true digestive system.
A foraging bee can store fresh nectar in its crop for transport back to the hive. Or, if the forager needs to drink or eat, it can pass the nectar onto the proventriculus to begin digestion.
You can see where it might be a little hard to understand, but it's no more mysterious than a queen deciding she will fertilize one egg but not another. Some things in the insect world are beyond our comprehension, but that doesn't mean they're not real.
The proventriculus is fascinating because it's a one-way valve. It allows nectar to pass from the crop to the actual digestive system, but not the other way around. In other words, bees cannot regurgitate the contents of their stomach, only the contents of their honey stomach.
So yes, the bees are regurgitating nectar, but it isn't vomit. Perhaps the source of confusion is how we think of the stomach. When it comes to bees, we would be better served referring to the honey stomach as the crop or ingluvies instead of a variation of the word stomach.
At the end of the day, honey isn't made from bee vomit. So do with that information what you will.