Crow story:
Once I was biking home from the university.
Close to home there are a lot of walnut trees which the birds and squirrels like.
They usually wait for car to crush them in the road, but not always.
While I was slowly going down this block, I saw two crows.
One would pick up a walnut and drop it from maybe 30 or 40 feet onto the road to break it.
However, the second crow was trying to get to the broken nut before the one that dropped it.
Therefore the dropper was flying around and scheming in a way that it could get to the nut first in the event that the nut broke.
The walnut was not breaking so they repeated this several times.