F Minus by Tony Carrillo for April 03, 2016

That looks like a hornets’ nest, but I just learned that honeybees will warn you by butting you before stinging: "You will usually get two warnings from the bees before they sting, but not always. First, they will buzz angrily around your head in an attempt to get you to leave. If you don’t heed this first warning, the bees will begin bump into your head. This is called “head butting”, and when this occurs a stinging event will happen if you remain in the area."