Talk:Raven Branwen/@comment-29684190-20190911191239/@comment-4010415-20190912013738

Crows and ravens can also do simple math, so if they see four humans go into a tent, and then three of the humans leave, they know there is still one human in the tent and won't approach until that fourth human leaves.

They're incredibly intelligent creatures, and they have been noted to learn human behaviors.