"Everyone wants a magnet! Horseshoe magnets may be the iconic look, we Exploratorium Store nerds know cow magnets are the best. They work great with our Iron Filings to recreate our classic Black Sand exhibit. (What's in a name? They're so-called because cows will sometimes eat metal scraps such as nails or wires while grazing, but if they've swallowed a magnet it will collect the metal and keep them safe.)" - Ryan.
Cow magnets are strong, permanent magnets made out of alnico, an iron alloy containing aluminum, nickel, and cobalt. They are very strong and are ideal for a variety of scientific experiments.
Cow Magnets are perfect for demonstrating the magnetic lines of force. Simply cover the magnet with a piece of paper, then sprinkle iron filings over the top and watch them form into the lines of force.
Have you ever wondered why they are called cow magnets? Ranchers feed these magnets to their cows. The magnet settles in the cow’s first stomach. When the cow accidentally eats bits of steel or iron, the magnet attracts the metal bits and holds them in its first stomach. If the sharp pieces of metal were to pass through the cow's digestive system, the animal would suffer what ranchers call “hardware disease.”
The Cow Magnet recommended for ages 3+.