When animals want to be let inside, they scratch the door and whine to get their owner’s attention.
But what happens if they are too small to be heard?
YouTube user “MouseAgility” specializes in training his pet mice. He then puts up the results for the entire internet to see. In this particular video, a mouse named Little Grisu has been taught to ring tiny bells when he wants his owner to open the door.
Watch the video above to see Little Grisu in action.