believe it or not, america s top young scientist is just 11 years old but has already lived through some frightening hurricanes. one in particular, inspired him to build a better mouse trap. a sandbag that doesn t have any sand. abc s matt gutman got a demonstration. reporter: peyton robertson has the enthusiasm of an infomerical king. here he is in his audition tape for this year s young scientist contest and the ingenuity of edison. i created a prototype. reporter: the 11-year-old from ft. lauderdale and his family huddled in a closet as hurricane wilma ripped over in 2005 watching as the storm brought flooding damage and death. peyton who s been solving math problems since he was 3 set off to solve a problem by himself. you want to start with the science room i set up upstairs. reporter: yes. okay. reporter: his invention a sandless sandbag. i use salt in my bag. so it would be heavier than any approaching water.