As you well know, bullets are designed to kill people. So far, so bad, but the metallic compounds in them also tend to leach into the environment and kill off plants and wildlife too.
At training facilities the world over, the US Army uses live ammunition to gear up their soldiers for combat. These bullets just remain in the wild, and do their damage. Deciding that enough is enough, officials are now asking for proposals to design biodegradable bullets that shall harm the environment no more.
So the next time someone is raiding your melon patch, if you get a shot off, you'll know who it was - Just wait three weeks and look for someone growing broccoli outta their butt.