Podcast: A planet beyond Pluto, the bugs in your home, and the link between marijuana and IQ

Summary: Online News Editor David Grimm shares stories on studying marijuana use in teenage twins, building a better maze for psychological experiments, and a close inspection of the bugs in our homes. Science News Writer Eric Hand joins host Sarah Crespi to discuss the potential for a ninth planet in the solar system that circles the sun just once every 15,000 years.  [Image: Gilles San Martin/CC BY-SA 2.0]