They were sharp.

They listened to what was being said around them, and the crows, you know, are the greatest talkers ever; so they soon knew the difference between a man with a gun and a man without one.

They knew that an owl in the daytime is not the same thing as an owl at night.

They gathered that a scarecrow is not as dangerous as it looks.

And many other things that a crow needs to know and believe they condescended to learn, because learning came easy to them.