Horizon discovers what your cat really gets up to when it leaves the cat flap.

In a groundbreaking experiment, 50 cats from a village in Surrey are tagged with GPS collars and their every movement is recorded, day and night, as they hunt in our backyards and patrol the garden fences and hedgerows.

Cats are fitted with specially developed cat-cams which reveal their unique view of our world.

You may think you understand your pet, but their secret life is more surprising than we thought.

50 cats were fitted with GPS collars to track their every movement, and cat-cams to record their unique view of the world. In this groundbreaking experiment, a few cats stood out.

They include the intruder cat, an unneutered tomcat, who comes into the village and seems to have no owner; the hunter, who prefers food that he can catch and kill to anything his owners might buy him; and the deserter cat who has abandoned his home in favour of a new set of owners.

This film reveals that the relationship between cats and their owners isn't quite what we imagine.