I have found a lot of newer pennies that i find are badly corroded and eaten away. My oldest coin to date was a 1888 indian head penny and i was very dissapointed to see that about 1/4 of the top was eaten away also. I was just curious as to what causes this. My first guess would be acid rain, but thats all it is is a guess. Does anyone know what causes this, and what do you do with all those BAD PENNIES. I was thinking of tossing them in the in the trash.