He set up the apparatus to "reward" the pigeon from time to time no matter what the bird did. Now all the birds actually needed to do was sit back and wait for the reward. But in fact... in six out of eight cases they built up--exactly as if they thought they were learning a reward habit--what Skinner called "superstitious" behavior. Precisely what this consisted of varied from pigeon to pigeon. One bird spun itself around like a top, two or three turns anticlockwise, between "rewards". Another bird repeatedly thrust it's head towards one particular upper corner of the box. A third bird showed "tossing" behavior, as if lifting an invisible curtain with ts head. Two birds independently developed a habt of rhythmic, side-to-side "pendulum swinging" of the head and body. ...
It was the pigeon equilivant of a rain dance.
--Unweaving the Rainbow by Richard Dawkins
* While the book certainly had its moments, I would recommend against reading it for reasons elaborated upon in my review on goodreads.