From the June 2006 Idaho Observer:
Aspartame – The World’s Best Ant Poison
contributed by Jan Jensen of WELLthy Choices
We live in the woods and carpenter ants are a huge problem. We have spent thousands of dollars with Orkin and on ant poisons trying to keep them under control but nothing has helped. So when I read somewhere that aspartame (Nutrasweet) was actually developed as an ant poison and only changed to being considered non-poisonous after it was realized that a lot more money could be made on it as a sweetener than as an ant poison, I decided to give it a try. I opened two packets of aspartame sweetener, and dumped one in a corner of each of our bathrooms. That was about 2 years ago and I have not seen any carpenter ants for about 9 to 12 months. It works better than the most deadly poisons I have tried. Any time they show up again, I simply dump another package of Nutrasweet in a corner, and they will be gone for a year or so again. Since posting this information I have had many people tell me of their success solving ant problems with this substance, when nothing else worked.
We found later that small black ants would not eat the aspartame. It was determined that if you mixed it with apple juice, they would quickly take it back to the nest, and all would be dead within 24 hours, usually. I have found that sometimes it will kill them, and sometimes it does not. Not sure why, may be slightly different species of ants or something. Fire Ants: We got our first fire ant hill about 2 weeks ago. Poison did not work. We tried aspartame and the ants ignored it until we got a light rain. It was just a sprinkle, enough to moisten the Nutrasweet and ground, but not enough to wash it away. They went crazy, hundreds of them grabbing it and taking it back into the mound. When I checked the mound 2 days later, there was no sign of the fire ants. I even dug the mound up some, and still saw none of them. How does it Work: Aspartame is a neuropoison. It most likely kills the ants by interfering with their nervous system. It could be direct, like stopping their heart, or something more subtle like killing their sense of taste so they can’t figure out what is eatable, or smell, so they can’t follow their trails, or mis-identify their colonies members, so they start fighting each other. Not sure what causes them to end up dying, just know that for many species of ants it will kill them quickly and effectively. As with any poison I recommend wearing gloves and washing any skin areas that come in contact with this poison, and avoid getting it in your mouth, despite anything the labeling may indicate. I suspect it will work for other insects such as yellow jackets as well, but have not tested that yet. More information on this fantastic poison can be found at: www.dorway.com