JR Mortimer is a frequent writer for National Geographic Kids. 

Matt Bellace, Ph.D., has been a youth motivational speaker and stand-up comedian since 1995. Dr. Bellace has a Ph.D. in clinical psychology (subspeciality in neuropsychology), is a member of the National Speakers Association and the author of the book, A Better High. His "How to Get High Naturally" program encourages over a hundred thousand students a year to make healthy choices. Matt was a recurring comedian on truTV's "World's Dumbest." His stand up can be heard - and requested - on Sirius XM's Comedy Channels.