Humans aren’t the only creatures that get frustrated. Squirrels do too. One researcher wants to know, could there be an evolutionary benefit to losing your cool?

This is another installment of the PBS Deep Look series. If no film or link appears in this email, go to the blog to view it by clicking on the blog title above. If the film stops & starts in an annoying manner, press pause (lower left double bars ||) to let it buffer and get ahead of you.  [Chuck Almdale]