As a chicken owner, I want my chickens to be as happy as possible. Happy hens lay better eggs, too! My hens look much better than commercial hens, and the eggs cannot compare. So it's a true win-win scenario, my hens are happy and we are happy with their eggs. Having had chickens for 3 years and counting, I've observed what can make them happy.
1. Provide enough space. The preferred square footage of room in the coop per hen is 3-4 square feet, but more doesn't hurt! My chickens have 10 square feet per chicken, and spend a majoity of their time using that space for dust bathing and foraging for bugs. It not only keeps them clean and full from eating bugs, but also reduces pecking-related injuries.
2. Provide the right nutrition. Laying eggs requires many nutrients, and it's very important to replenish those lost during the daily egg laying cycle. Be sure to provide clean water, the correct food for your flock, free-choice calcium supplements (oyster shell, ground up egg shells), and a few treats here and there. I've found that giving my chickens scratch every other day is enough to fill them up and make them happy, but not too much to where they wouldn't eat their layer crumbles.
3. Protect them from the elements. Winter snows and summer heat can really take a toll on your chickens. Make sure that your coop can help keep them warm in the winter and cool in the summer. Install insulation with a face, or protective paper-like layer on the outside, to keep heat in. Also install a perch that has the wider side facing up so that they can sit on their feet and keep them warm. In the summertime, make sure you have enough ventilation to allow a nice breeze in and heat out.
4. Keep it clean. A clean coop not only smells better to the nose, but also has less ammonia present. Ammonia can cause respritory problems in both you and your chickens. I also suggest cleaning out the nesting boxes often so that the eggs are laid in a clean and padded environment. My chickens will sleep in the nesting boxes (it makes them happy and isn't much trouble, so why not) so I go in every morning and scoop out all the poop.
5. Reduce stress. Predators and drastic changes in environment can put stress on a chicken, making them decrease or stop laying. Ensure that your coop is protected from predators like hawks, foxes, raccoons, bears, coyotes, snakes, etc. Our chicken coop has a top covered with chicken wire that no aerial predator has gotten through. We also put a double layer of fencing around the coop and concrete at the bottom of that to deter predators.
6. And last, but not least, interact with them. Chickens will love seeing you if you pet them and are friendly around them. They may even go as far as to think your arm is a warm perch or your back is a floor! It'll bring a smile to your face.