Do you know what is in this picture?
No, my dear Mad Scientess, I do not. It doesn't look like something you should be waving around at work, either.
Yes, I do, and I will reveal my answer in the text box.
It's a cow magnet. These are fed to calves and sit in their stomachs collecting the metal objects that cows ingest when they graze. Cows have a habit of eating whatever they happen to pick up, which includes nails and barbed wire. Obviously these items are not good for their intestinal tracts. The magnet remains in the cow's stomach for its lifetime.
The practical upshot for people who work in space-based instrumentation is that they cannot build magnetic cleanliness testing facilities in fields containing cows. Sheep, on the other hand, are fine.