An Ufo landed on earth and the extraterrestials got welcomed by the locals.....
Things got on ok, and communication was no problem...
Comparing life on their planet vs ours, the eartlings asked how the "marsians" reproduced.....
"easy" the marsian said, and he popped a pill out his pocket, and threw it onto the ground....
A few seconds later there was a new little marsian.....
Well, all the people commented on how civilised and advanced it was compared to our "primitive" copulations

Intrigued,the marsians insisted to know how , so a young couple decided to get on with it and showed them how we reproduce here.....
After a few minutes , the marsians burst out laughing, slapping their knees, tears roling down their cheeks...

The couple gave up their efforts and asked "what's so funny ?"
Well, said the marsian:
"that's how we make our pills......"