Is it playtime or naptime? That depends on which of Zoo Atlanta’s impossibly cute 4-month-old panda cubs you ask.

Mei Lun is feeling sleepy, but Mei Huan is bright-eyed and ready to rumble.

Check out his adorable antics in the video below, and read our story on how the breeding approach of “twin swapping” that the zoo used is helping the critically endangered species.

Watch more Vetstreet funny animal videos.