My post about Sweet Pea and Gertie's encounter with a fierce jungle cat generated some interest and I want to take this opportunity to elaborate a bit on the topic. OK, so it wasn't a fierce jungle cat, just my Mom's Maine Coon mix, Beau. He is a reformed city cat and has adapted to life in the country quite well.
There is another cat who lives here on the Twelve Acres. He's my old buddy, Tyson. I adopted him from the Humane Society 11 years ago and he's gone everywhere I've ever lived. He's missing two of his fangs and he's an old man; not much of a threat to most critters. But he does exhibit the stalking behavior common with most domestic cats, even though he disdains the chicks.
When the chicks were only a day old, I introduced them to Tyson. I held him gently but firmly in my left arm while sitting on the floor. I held a chick in my right hand and put it close enough to Tyson's face for him to get a good sniff, but far enough away that he wouldn't be able to snatch the chick if the desire struck. It went well. Tyson's ears pricked up in keen interest and he got the distinct "predator look" on his face that cats get right before they grab their prey. I talked to Tyson and let him know with my tone of voice that the chicks were off limits. Tyson's body language changed from "predator" to "passive" within seconds. He's a smart cat and he knows me, so when I set boundaries, he's a good boy and respects them. Beau's not quite as sharp, but knows when he's gone too far by the sound of my voice.
To err on the safe side, no cats were allowed in the house unsupervised for the four days the chicks were inside. They were moved to their coop at five days old, so the cats were allowed back in after that. I checked on the chicks each night before going to bed, and I would let Beau in with me sometimes. He was more interested in checking out the coop's interior than snarfing down a fluffy chick, though. Did I mention he's not very sharp?
Now that the chicks are 6 weeks old and have grown larger, the cats don't exhibit that hunting behavior anymore. Now they are just content to sit and watch "Chick TV". The chicks are still alert as ever and sound the alarm whenever they see a cat, but the cats aren't a threat. I had to be vigilant the first few encounters, but now I forget about the cats wandering around in the yard.
Cats can be taught that the chicks belong to you and are off limits. Introducing them carefully and asserting yourself as the dominant critter will work. The lessons may have to be repeated several times, but the cat will learn. Something that would work really well for training cats to leave chicks alone would be an accurate squirt gun. If the cat gets too close, a shot of water in the face will instantly associate a very unpleasant experience with the chicks.