A humane cat trap is very simple metal cage. The cat enters the trap, triggers the trap mechanism and the door closes behind it, trapping it inside. In the UK, a cat trap has to be live catch by law.
A live catch cat trap is not only more humane but allows for non-target species such as dogs, badgers or even squirrels to be released safely and unharmed. It too allows for cat to be re-located and released safely.
Here are the basics of our collapsible cat trap