While it is not clear what prompted a biologist to invite other biologists to post pictures of animals genitalia in a #JunkOff, it did get a good few posts, but when the challenge shifted to try find the cutest, things really took off.
The posts quickly got additional tags depending on the order the animals belonged to so the #TeamMammals, #TeamHerpetology and #TeamIchthyology were all trying to "out cute" each other.
You can see even more on Twitter
This article first appeared on 702 : Which animal is the cutest? Biologists on Twitter have a #CuteOff battle.