Look up “natural” ant repellents online, and you are bound to find cucumber listed as an easy home remedy to ant infestation. Is there any truth to this? A National Taiwan University entomologist, Prof. Matan Shelomi, discovered that there was no actual scientific evidence for or against this claim, so he decided to test it himself. The results, using cucumber peel extracts in different solvents, were underwhelming.

“While some extracts did have detectable effects on the ants,” says Shelomi, “the effects are weak and likely very short lived.” Less than half of the ants seemed bothered by the cucumber at any given time, and there was nothing approaching the miraculous repellency promised online. In a recent paper in the journal Sociobiology (68[2]:5813), he wrote, “Cucumber may indeed repel some ants, slightly, sometimes,” for at least fifteen minutes, so not exactly promising … and that was with chemical extracts of peel. Whole cucumber is probably even less effective: “Ants readily eat cucumbers,” says Shelomi, “so spreading cucumber slices around your home is like giving ants a free buffet.”

The study not only busted an old myth but also criticized “natural” remedy research in general. “There are so many papers, of varying quality, where researchers take whatever plant or food they have on hand, extract oils from it, and test it on insects or microbes or whatnot using ridiculously high concentrations in unrealistic conditions,” says Shelomi. “Then, as long as they find something with a significant p-value, they call it a ‘promising’ new treatment.” Such research does not provide practical information and almost never includes safety information.

So what to do about an ant problem? Shelomi recommends sprinkling a mixture of sugar with borax or boric acid near the colony, which will kill the ants without posing any risk to humans or pets. Unlike cucumber, borates are safe, effective, and supported by evidence, plus they are still natural—if one values that word.