Charge across the room, barking loudly, and leap playfully on this person. Always take a BIG drink from your water dish immediately before licking your human.
Humans always prefer clean tongues.
So bark - a lot. Your owners will be very happy to hear you protecting their house. Especially late at night while they are sleeping safely in their beds. There is no more secure feeling for humans than to keep waking up in the middle of the night and hearing their protective dog barking and barking and . . . There are never enough holes in the ground.