Who would have thought mice would be a vector for seed with a poisoned seed coat, a.k.a., treated seed?  When my father first ordered his garden seed for last year, he swore he got untreated seed, had checked the box on the order form for untreated seed, and so he had.  Unfortunately, the seed that arrived was treated.

Treated seed…treat with caution.

According to the FDA‘s website, these are some of the labeling requirements for treated seed:

Section 201.31a (d) of the FSA regulations requires seed treated with a chemical not assigned to Toxicity Category I by EPA to be labeled with, “Do not use for food,” “Do not use for feed,” “Do not use for oil purposes,” or “Do not use for food, feed, or oil purposes,” if the amount remaining with the seed is harmful to humans or other vertebrate animals. The most commonly used labeling for seed with these types of seed treatments is “Treated with (name of substance)” and “Do not use for food, feed, or oil purposes.”

The type of seed treatment we have is dangerous to birds, and therefore would be dangerous to our chickens. I looked online for other views on treated seed and birds, and I found this from Michigan, as well:

The neighbor next to me planted 40 acres 12 days ago, and filled in some wet spots a few days ago. I walked down my lane two days ago and found two crows 30 yards apart in the fencerow. They are both dangling from limbs several feet off the ground. Wings wide open, drool hanging out of their beaks. Very close to death. I am sure they ate too much treated corn seed. Not a pretty site. They are a few feet from my neighbors newly planted corn field. (Michigan Sportsman Forums)

The forum also included a section about how this man’s field was sprayed with Round-up, obviously not healthy to birds, but the treated seed caused death of crows. The treated seed at our garden was stored in a shed that was infiltrated by mice, who infiltrated treated packets, and we began to find dead mice on the floor, in boxes, and in corners.  Unfortunately, we also found mice droppings and the remnants of coated, treated, seed shells under our packages of oyster shells in our shed.  We tried to put out oyster shells, but we found blue flecks in them, and upon closer inspection, we found that the treated seed had been spread by the mice to our mineral salts for the birds, as well. Even stored treated seeds have the potential to adversely affect your birds if mice carry them around.

Here is the warning for Syngenta, a treatment to prevent fungal infections in plants:

DO NOT use treated seed for animal or human consumption. DO NOT allow treated seed to contaminate grain or other seed intended for animal or human consumption.
DO NOT feed treated seed, or otherwise expose, to wild or domestic birds.

When treated seed is stored it should be kept apart from other grain and the bags or other containers should be clearly marked to indicate the contents have been treated. Bags which have held treated seed should not be used for any other purpose.


DO NOT feed treated seeds to animals, including poultry.

This product is toxic to fish and aquatic invertebrates. DO NOT contaminate streams, rivers or waterways with the product or used containers.

This segment was taken from the Syngenta website. Apparently we are not the only people noticing the toxicity of these seeds. We ended up dumping all of our products that the mice had gotten into anyway–who would want to feed mouse poop to their chickens–but we never expected the treated seed to be spread by the mice to multiple locations.  We thought we had the seed stored safely away from our garden.

I, personally, never handle treated seed, nor do I allow my daughter to handle it. I get too nervous about the toxicity of these chemicals on treated seed.  If the seed is so toxic, then why use it or touch it, but I just wanted to offer a cautionary tale that even storage of these seeds can result in spread by vectors we might not foresee.