The clip, which has received over 724,000 likes at the time of writing, shows a human hand tapping the top portion of a staircase while a seemingly nervous chihuahua looks on from the side of a wall.
A video of a dog appearing to help a smaller dog go down a flight of stairs has gone viral on TikTok.
The video then shows the chihuahua halfway down the stairs, as another dog is seen at the bottom of it, tapping its paw occasionally.
A caption shared along with the post said: "After watching the video, I noticed the sweetest moment of Kevin tapping the stairs like he saw me doing. #bestfriends #dogsofttiktok #chihuahuastiktok #learning #HPSustainableSounds #rescuedog #fyp."
A message on the video read: "I was so focused on getting Mila to try the stairs that I didn't realize Kevin had learned to tap the step to encourage his sister."
A July study
A July 2018 study published in the peer-reviewed journal Learning & Behavior stated. "Dogs have been shown to provide help to a fellow dog in a situation where they would not do so for a human."
Their "reputation for emotional sensitivity" could be down to their "unique ability to respond to human social cues."
The study said, "empathetically-motivated prosocial helping." Observed in dogs "sometimes appears to be motivated by a desire for social contact alone."
However, it "follows human patterns of empathetic helping in distress conditions," the study explained.
As Kevin's latest video demonstrated, dogs are brilliant beings with superb learning abilities.
A July 2018 study in Scientific Reports explained that "adult dogs are known to excel in social learning skills."
The study found that these skills "were present in 8 weeks old puppies. And they remembered this experience for 1 hour."
It also said "puppies were more likely to learn from unfamiliar conspecifics than from their mother," probably due to the greater attention given to the demonstration performed by "the unfamiliar model."
The latest viral video delighted users on TikTok, with several moved by the dog's touching gesture.
The comment that received 564 likes
In a comment that got 564 likes, user Xio said: "I'm crying [flood of tears emoji]."
User alma90loya wrote: "Kevin looked so happy when Mila was using the stairs." And Amber Johnson added: "Kevin is the 'goodest boy'!!!"
User Brownie-Dragonsfairy remarked, "that is beyond sweet. He's a good brother" — while leeannholcomb shared, "oh my goodness [floating hearts smiling face emojis] that just warms my heart!"
Jennifer Redden noted: "That is THE sweetest thing I have seen [red hearts emojis]."
User Waves and Sunsets agreed: "How sweet and smart and thoughtful."