More than five million animals are used in experiments in Britain every year. At the end of the experiments the animals are killed. It's claimed most of them are used to make sure our environment is safe - what we eat, what we breathe, what we take when we are ill. But that assertion is challenged by an increasingly vocal animal-rights lobby - which says most experiments are unnecessary, cruel or trivial. Man Alive has filmed in laboratories round the country to find out what we do to animals. And, in the studio with reporter Michael Dean will be people who perform experiments and those who say it's time they were made to stop.