PepsiCo offered an interesting defense to the mouse in Mountain Dew lawsuit -- their products are so bad for you that the acids in the soda would have dissolved the mouse into nothing before the consumer could have possibly opened the can of soda and found the dead mouse inside.
Roland Ball said he purchased a Mountain Dew from a vending machine and began to drink the can when he "tasted something foul" and spit out the soda, reports KSL TV. Ball said he poured the contents of the can into a Styrofoam cup and discovered the remains of a mouse.

