There are many predators for chickens. For instance dogs, coyotes, cats, foxes, raccoons, weasels, skunks, opossums, snakes, owls, and hawks. We mostly have problems with hawks trying to get the chickens on the farm. We want the chickens to safely be able to forge for bugs.
Hawks will attack any time during the day. Hawks have extremely good eyesight and will scope out areas from high up in the trees. Once a hawk finds its prey it will go in for an attack. Sometimes hawks will pick up the chicken with their talons and take off with them but they will also pin them down on the ground and use their talons to kill them on impact. Unfortunately, there are usually not any signs of an attack; you will just notice you are missing a chicken.
There are many different ways to keep chickens safe. You can build safety shelters like chicken tractors, or chicken runs. They keep them safe but with everything there is always cons. If chickens are in a small area they will destroy the ground and it will eventually just be dirt. We prefer the chickens to free range.
I have heard of people using reflective ribbon, and pinwheels to scare off hawks. The sunlight will shimmer on the ribbons and will make the hawks nervous to approach the area, and as wind blows it will make noise. These options usually work temporarily but the hawks are very intelligent and will figure it out.
Even though dogs can be a predator, they can also protect them. Live stock guardian dogs are or can be trained to protect animals on your farm. The dogs can intervene an attack or even alert you of an attack. But hawks can even carry off small dogs so you would have to have a larger breed dog.
You can make a scarecrow and set it up to deter the hawks from coming into the area because they think it is a human. You cannot just set it up and you are good to go from then on. You will have to periodically move it to different spots.
When I was at the farm last we tried letting the chickens out to free range and it did not go as well as we had hoped. We had previously seen a couple small owls but we had also seen several hawks. Unfortunately, when my parents went to put the chickens back in the coop there was a hawk devouring a poor chicken. Now I know it happens but we try to do everything we can to keep our animals safe and we started researching what to do.

My dad recently made a scarecrow (maybe he was inspired by all the fall decor I put all throughout the house haha). If you know my dad you know he loves vibrant colors, and Hawaiian shirts as you can see above. So you know he made a Hawaiian scarecrow. So far the last couple days it has kept the hawks away from the chickens.

Time change is coming soon and it will be getting darker earlier so it was time to add more lighting to the bathroom. My dad has been doing an amazing job with putting in the electrical, I know it is much more difficult with trying to put in into finished walls. I am so excited for each and every improvement on the house. Let their be light! 

