Garden Myths Gardening Harmful animals

Garden Myth: Cornmeal Makes Ants Explode

20170716AEN.jpgThere are all sorts of garden myths, but one of the strangest is certainly the one that suggests if you put out cornmeal, it will make ants explode.

According to this urban legend, when ants eat dry cornmeal, it will expand in contact with the liquids in their digestive system, creating so much pressure that they explode! A variant of the legend claims that ants die instead from flatulence. And yet another insists that it’s not cornmeal that you should feed ants if you want to kill them, but grits… or a mix of cornmeal and grits.

Obviously, this is all nonsense. Do you really think that the ants will start exploding like firecrackers because they ate something? In fact, cornmeal and grits make wonderful ant foods.

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Commercial ant baits are often made of a mix of cornmeal and boron.

It’s easy to understand where this legend comes from. Commercial ant bait is often made up largely of cornmeal… not that cornmeal kills ants, but because they love it! It’s not the meal that kills them, but the insecticide that the producer mixed into it.

Worker ants can’t eat ant bait (i.e. cornmeal) because it’s a solid and they can only eat liquids. The queen ant too only eats liquids. So there is no danger they’ll eat the cornmeal bait themselves, then die of explosions or farting on their way back to the nest. Instead, they bring the poisoned meal back to their nest’s larvae and they can consume solids. They chew it up, partially digest it, then regurgitate the sweetened liquid that results from their digestion. This is the liquid the workers eat and that they feed to the queen.

If the larvae ate poisoned bait, one containing a weakly toxic product (usually boric acid is used), something that won’t kill them outright, and the queen eats it, she’ll be poisoned little by little and will eventually die. But only if the cornmeal contains a toxin.

It’s not the cornmeal that kills ant colonies, but the toxic product that is incorporated into it. If you simply apply cornmeal to the soil, as per the urban legend, you won’t be killing the ants, you’ll be feeding them.20170716AEN

Larry Hodgson is one of Canada’s best-known garden communicators. He has notably been editor-in-chief of HousePlant Magazine, Fleurs, Plantes et Jardins, À Fleur de Pot and Houseplant Forum magazines and is currently the garden correspondent for Le Soleil and radio garden commentator for CKIA-FM Radio. He has written for many garden publications in both the United States and Canada, including Canadian Gardening, Harrowsmith, Horticulture, Fine Gardening and Organic Gardening. He also speaks frequently to horticultural groups throughout Canada and the U.S. His book credits include The Garden Lover’s Guide to Canada, Complete Guide to Houseplants, Making the Most of Shade, Perennials for Every Purpose, Annuals for Every Purpose, and Houseplants for Dummies, as well as nearly 60 other titles in English and French. He is a past president of the Garden Writers Association (now Garden Communicators International) and the winner of the prestigious 2006 Garden Media Promoter Award offered by the Perennial Plant Association. He resides in Quebec City, Quebec, Canada.

10 comments on “Garden Myth: Cornmeal Makes Ants Explode

  1. Pingback: Garden Myth: You Can Kill Slugs With Cornmeal – Laidback Gardener

  2. mack1946

    Thanks for the post. I thought it might be wishful thinking. I think I’m gonna try Sevin dust. I saw where some folks had used it and it didn’t seem to hurt the chickens. But again thanks for the info..

    • Racchel Racchel

      don’t use Sevin if you have pets. I had three baby tortoises die because they ate a very small amount of Sevin. The ants may not explode, but cornmeal has done the trick and is safe for other pets.

  3. And yet every fireant pile I’ve ever dumped cornmeal on has been completely eradicated after 2 weeks. Every single one. Ever single time.

  4. Pingback: Marijuana Pests & Bugs – Control and Identification | The One Thing Growing

  5. Before you bash something observe and understand it. Prove your theory.

  6. It’s not true that ants only eat liquids. Put a few dry cat kibbles in a jar lid, and watch what happens.

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