I've seen some pricey chicken feeders and waterers for sale promising to protect the feed from rodents, sparrows and from the chickens pooping in the feed. But you can easily make a chicken feeder/waterer for free for a small flock of hens.
Below is photo I took of a 2L plastic milk bottle that I converted into a feeder. For this one I used a hacksaw to saw the top off at an angle to allow the hens to reach in. I've found its actually easier to just use a Stanley knife (or kitchen knife) so that's what I've used for subsequent models.
I tied a piece of fine rope around the handle and tied the feeder to the wall in the chicken coup so that the container hangs about 5cm (2 inches) off the ground. My hens can easily eat out of it but rodents would have a hard time climbing up to the food. Its also harder for sparrows to steal the food since its difficult for them to land on this feeder.
For water, I hang the bottles in the outer run where I can easily refill them with my watering can each day. I place several of these feeders and waterers around to ensure that there is enough food and water for all of the hens (we have five hens). One of our hens is a bully and hogs the food, but by hanging these feeders around in different corners, it prevents her from hoarding a single food source.