Place about 5 fake eggs ( for example pottery or rubber eggs) in a normal nest in you chicken coop.
WAIT! until one of your precious hens decides to be a mommy :)
you can be sure, that you have a broody hen when she:
- ruffles her feathers
- makes noises that remind of water in a bottle ( "glug glug")
- leaves the nest only for a few minutes a day and returns to the eggs very fast
- gets angry when you come near her ( she picks)