Why does brown rat have strong teeth and it is comparable to steel

Rat teeth are ranked 5.5 on this scale, which means their teeth are harder than copper and iron. The jaw muscles of a rat can exert up to 12 tons (or 24,000 pounds) per square inch. By comparison, a great white shark bites with a force of 1.8 to 2 tons per square inch

. The scale ranks from 1 (softest, such as Talc) to 10 (hardest, such as Diamonds).  Rat teeth rank about 5.5 on the Mohs Scale, harder than iron or copper.  Human tooth enamel only ranks about 5 on the Mohs Scale.  Because their teeth are so hard, rats are able to chew through most of the materials people use to keep them out, such as:

explanation:

shower, toothbrush, toasters, refrigerators,   and the lights

you use the lights to see and brighten a room. and with out them you cant see. you need a toothbrush to clean your teeth with out it stinky breath. shower to wash ya self and without it you stink. toaster to toast stuff without it nothing is toasted. and the refrigerator to keep stuff cold without it everything goes bad