That reminds me of a story. The author Elizabeth Moon and her husband kept horses, and one year they decided to get oats for the winter instead of hay. They didn't realise that oats need to be stored differently, not just in a pile on the barn floor.

They took one of their horses to the vet because he developed a persistent cough; the vet asked a few questions. When he heard how they were storing the oats, his eyes widened, and he leaned forward. "You need to get rid the oats. Now." Then he explained why...

So as soon as they got back they started shoveling the contaminated pile of oats into bags to depose of it. And as they did so, first a few, then a stream of mice started running out of the pile of oats. Their hair was standing on end from disgust, but they had to keep shoveling. At the sound, the cats came from all the nearby farms, so that they were at the centre of a ring of cats; but by the end all the cats had eaten so many mice that they were stuffed; and could only lie there, and watch the mice go by.