The Kepler mission has transformed our knowledge of the properties of extra-solar planets. It has told us a dominant - perhaps the dominant - population of exoplanets are those close to their parent stars with masses in the range 1-20 M_earth. Unlike the low-mass, close-in planets in our solar system these exoplanets are thought to contain voluminous H/He envelopes. I will discuss the evolution of this population of exoplanets, particularly with regard to mass-loss. It appears that as soon as these planets finish forming, and their parent disc disperses they begin a lifelong period of mass-loss and evaporation which imprints itself on the population we see today.