Pull out your art supplies because it's time to get crafty—with agar! We're beginning Arts Week at the intersection of biology and art. Therein lies a creative medium that's actually alive. Scientists and artists practice etching designs on petri dishes with bacterial paint that can grow and multiply. This encore episode, Aaron talks with science correspondent Nell Greenfieldboyce about her foray into the agar art world. Love the science powering another craft? Email the show at shortwave@npr.org.