The moon. The moon has a long association with being crazy (lunar being the basis for a lunatic). It shines at night, when you go to bed. The moon’s gravity creates the ocean tides and when the moon is different colors it can mean bad weather is on its way.
A worm. Worms don’t have eyes or ears, but they can sense light and their bodies can detect vibrations in the ground. Fishers use worms as bait and the term bookwork is used for someone who loves to read.
Suppose a small bank has one teller and customer transactions take 10 minutes on average. With 5.8 customers arriving per hour, what is the expected wait time? What would it be if you added a second teller?
A completely black dog was strolling down main street during a total blackout affecting the entire town. Not a single streetlight had been on for hours. As the dog crosses the center of the road a Buick Skylark with two broken headlights speeds towards it, but manages to swerve out of the way just in time. How could the driver see the dog to swerve in time?