Mouse and Crow
There was once a crow who was very hungry. Flying over the tops of the trees, it spotted a large, tasty-looking walnut growing from one of the tallest branches below. Seeing the makings of a fine supper, the crow swooped down and plucked the dangling walnut and held it triumphantly in its beak. The crow flapped its wings happily, and began to think about how best to break open the shell of the walnut.
Meanwhile, on the ground below the crow, an equally hungry mouse saw everything that had happened, and decided that it wanted that same walnut for itself. With a plan that was clever, though not particularly nice, the mouse called up to the crow high in the tree, "Say there, friend crow, what’s that you have in your beak?"
The crow, who was hungry enough by now that it wasn’t thinking all of its decisions through very well, called back, "I've found a very nice walnut, and am going to eat it." When the crow opened its mouth to say all that, the walnut fell out of it, and dropped to the ground, just as the mouse had hoped it would. But the mouse didn’t count on where the walnut would land when it fell: it hit the ground and rolled into a shallow hole.
The mouse ran to the hole, and reached in to pull out the walnut, so that it could crack the shell and eat it. But the hole was just small enough that the mouse could not pull it out. With both its paws wrapped around, the walnut was too wide to get back up out of the hole. The crow, meanwhile, was unhappy at having been tricked out of its supper, and began to shout at the mouse down below, who couldn’t leave because it was still holding on to the walnut, trying and failing to pull it back out of the hole in the ground.
Now, if the two of them had worked together, they both might have gotten to enjoy some of that walnut: the crow could have pecked its sharp beak down into the hole and broken up the walnut into smaller pieces. Then the mouse could have reached in and picked each piece out one at a time. But instead, the two of them were stuck there, arguing with each other and both still hungry: the mouse because it couldn’t let go, and the crow because it couldn’t hold on.