The Idaho Statesman reports that federal law makes it illegal to use seeds or grain to lure waterfowl for hunting unless the seed or grain was already there from normal agricultural harvesting.

The law is meant to protect the birds from overharvesting.

According to the Nov. 10 indictment of farmer Gregory Obendorf of Parma, Idaho, U.S. Fish and Wildlife Service agents began investigating after flying over Obendorf’s land and noticing several piles of corn kernels near a duck hunting blind.

Julie Klein Fischer, one of Obendorf’s attorneys, called it troubling that the government decided to indict the farmer instead of handing out a wildlife violation.