A flatworm sent into space in 2015 returned 5 weeks later with two heads, one on either side of its body. Flatworms are well known for being able to regenerate after being cut into pieces. Scientists cut a number of flatworms into pieces and sent them into space to study the effects of space on this regeneration process. They were in for a surprise when one of the amputated worms returned with a second head where its tail should have been. (http://bit.ly/2GqMjqc)