A smart pet dog learned how to retrieve his owner's house keys to help him when he is locked out.

Footage shows the three-year-old Chihuahua pooch Noddy being trained to hand over the object to Thirachai, who knocked outside the gates in Nakhon Pathom province, Thailand, on July 29.

Noddy stood still in the room and waited for his caretaker to return until he pointed to the objects on the table.

The well-focused dog then did as he was told and circled around the room to search for the keys before he found them and gave them to Thirachai.

Chihuahuas have a higher brain-to-body ratio than other dog breeds despite their small size. They are very intelligent and have a great capacity for learning.