These sweeteners also spoil more rapidly and can make the birds sick. You may not even realize that you are making the birds sick because they won’t die until several days after they have ingested the spoiled food.
The pests may crawl into the feeder where they can become trapped and drown. You can help prevent ants from crawling into your feeder by using Vaseline on the wire it hangs from so they can’t get to the nectar. As for bees and wasps…sorry, can’t help you there.