Magnets are objects that attract pieces of iron or steel. In ancient times, people first discovered magnetism when they found some naturally magnetic pieces of rock in the earth that other materials can be magnetized as well. Nickel, cobalt, certain types of ceramics and certain blends of metals can also make good magnets. They called these rocks lodestone. Loadstones have a lot of iron in them, but we now know that if you could look at a magnet at the atomic level, you would notice that the magnet was divided into a number of smaller regions called domains. All of the atoms in a domain point in the same direction and, since each atom acts like a little magnet, all of their little magnetic fields add together to make a larger, stronger field. A magnet can be weakened if some of its atoms are thrown out of alignment. Hitting or heating a magnet is usually enough to scramble some of its atoms.