The persistent home remedy suggesting that common kitchen grits can eliminate an ant infestation is a widespread piece of folk wisdom. Grits, a coarsely ground corn product, are often proposed as a simple, non-toxic form of pest control. The question is whether this popular urban legend has any scientific basis. Answering this requires understanding the specific mechanism the remedy describes and the fundamental biology of the ant itself.
The Common Belief: Internal Expansion
The theory behind the grits remedy is based on a dramatic physical mechanism. It is believed that foraging worker ants consume the dry cornmeal, mistaking it for a suitable food source. The claim is that once the dry grains are inside the ant’s digestive system, they swell dramatically when they encounter internal moisture. This expansion is theorized to cause fatal internal pressure, often described anecdotally as the ant “exploding” or bursting internally.
The idea is that worker ants carry the grits back to the colony, feeding them to other nestmates, including the queen. This would, in theory, lead to the widespread death of the colony, eliminating the entire infestation. This simple, non-chemical solution holds considerable appeal for many homeowners. However, the ant’s specialized digestive system makes this scenario biologically impossible.
Ant Digestive Biology and Liquid Diets
The biology of adult worker ants prevents them from digesting solid particles like dry cornmeal or grits. Adult ants rely almost entirely on liquid food sources for sustenance, an adaptation reflected in their internal anatomy. When an ant consumes food, it first passes through the proventriculus, a valve-like filtering structure located between the esophagus and the midgut.
The proventriculus acts as a barrier, filtering out large, solid particles and preventing them from passing into the midgut where digestion occurs. Only liquids pass through the proventriculus into the true digestive tract. Any solid material ingested, like a grain of grit, is filtered out and compacted into a pellet within the specialized infrabuccal pocket. This solid waste is then discarded outside the nest, not digested.
The worker ant’s primary role in feeding the colony is through trophallaxis, the direct, mouth-to-mouth transfer of liquid food. Foraging ants store liquid food in their crop, often called the “social stomach,” and regurgitate it to share with nestmates, larvae, and the queen. The entire colony operates on this shared liquid diet, meaning solid, expanding grits cannot enter the system that feeds the queen or other adult workers.
Practical Outcomes of Using Grits
Given the ant’s inability to process solid food, the results of using grits as a poison are predictable. When dry grits are placed near an ant colony, they may attract ants due to the cornmeal’s carbohydrate content. However, instead of being ingested and causing death, the grits are often ignored, used as building material, or only the liquid components are extracted.
Anecdotal reports of the method “working” are often attributed to other factors, not the grits themselves. Disturbing a colony by dumping a pile of foreign material near the nest may cause ants to temporarily relocate, giving the appearance of elimination. The natural ebb and flow of a colony’s activity may also simply coincide with the application of the grits, leading to a false conclusion of success.
Effective ant baits work because they utilize the ant’s liquid-sharing behavior, trophallaxis. These commercial products consist of a sweet or protein-based liquid mixed with a slow-acting poison. This poison is easily carried back to the nest in the worker’s social stomach and shared among the entire colony. Grits are sometimes used as a carrier in homemade baits, but elimination is achieved by the added toxic ingredient, not the cornmeal itself. Ultimately, dry grits are harmless to the ant and an ineffective tool for pest control.