Fake rubber eggs
To show a hen where to lay eggs fake rubber eggs are left in a nest. Chickens are not smart.
A friend tried an experiment: How many people need to be staring up in a group, before a stranger will stop and also stare up?
The answer was four. When four people stood around staring up, most strangers will stop and stare up with them.
At least we are four times smarter than chickens.