I'm also a beekeeper. The bees are looking for a protein substitute. It's common usually in the early Spring. It's not a big deal. Even dozens of bees. They can only take the 'powder' of the feed. One option is to take the crushed powder from the bottom of the bags, and put it in another feeder elevated. The bees will go there instead of into the chicken's main feeder.
In general, the chickens don't like the taste of a bee. Funny story, I usually have 100 dead bees up on my dashboard, bees that get into the truck when checking my bee yards. Call them dehydrated, freeze dried, crispy critters... I've tasted them. Nice and crunchy, but fairly tasteless. Note, you can still get 'stung' by a dead bee. Why did I do it? Well, beekeepers are just weird sometimes. I've read where bees are used as a insulin replacement (I'm not diabetic), and I was curious what the flavor would be. Nope, they don't taste like honey! (But I hope you enjoyed a chuckle!)