A video of a tortoise helping its friend has been going viral, but it may not be as heroic as it seems.
The video's uploader said: "We were all very lucky to see such kind of scene - one tortoise saves the other one's life!"
Despite the apparent act of kindness assumed by many viewers, National Geographic reports that this may just be an act of "aggressive courtship".
The footage comes from Taiwan's Taipei Zoo, where children scream with joy at the sight of the tortoise appearing to save its companion.
When asked about the animal's behaviour, turtle and reptile expert David Steen said that tortoise mating rituals can be particularly aggressive.
"It may be a matter of wearing down the female. It's not too romantic," he said.
"You can see that the 'hero', if you will, follows the other one away. That leads me to suspect that it's a male looking to breed with the female."
Under the video, uploader Au Di Yu said: "It's a great opportunity to give my daughter a lesson - Helping others is the origin of happiness."