Ralph the cloned rat was created by a team of researchers at the National Institute for Agricultural Research in France, working with a biotech company, genOway. Details of their work was published in the journal Science and announced to the world in September 2003.
Ralph was the latest in a long line of animals to be cloned and really came some way after the cloning of other species.
The main reason for this was a huge technical hurdle that was proving difficult to overcome. Rats' eggs start the developmental process almost as soon as they leave the confines of the ovary. That made it extremely difficult to introduce donor genetic material. Eventually researchers were able to stabilise this by chemical means, and the world's first cloned rat was born.
Since that time Ralph has fathered healthy pups, again showing that cloned animals can create normal, healthy offspring. To date there haven't been any reports to the contrary.