If that is not possible in some areas along the perimeter, sink 8" planks to prevent predators from scraping underneath. If foxes roam the area get the thickest chicken wire possible. Foxes have teeth that are as sharp as wire cutters that could easily cut through thin chicken wires. Normally animals could jump as high as their heads when standing on hind legs. After two weeks, the chicks will still need the extra heat but reduce the hours that the lamp is on especially during summer months. The chicks will outgrow the box and you will need additional accommodation for them. Even so, provide a lamp where they could huddle together and get heat especially in the coldest hours of the morning or and when they need it, otherwise turn the lamp off to get them acclimatized to normal temperatures. Each hen will also need a perch about 9" long. The design should also include a hatchway, storage area, ventilation, lighting and a feeder system. For a cleaner and healthier environment, design the floor to accommodate deep litter. This is normally done by piling three to four inches of wood shavings under the floor. Chickens could get by very well with one measure of mixed corn with one measure of pellets. If you can throw in other food, they will pretty much eat that too and if they do, there is no cause for worry. Chicken eats grit too. They need grit to aid their digestion. If you do not provide them that, they would be pecking pebbles. This is no cause for worry though as the feed is basically made of the same mixtures and components, the differences accounts for the degree of coarseness of the milling only. As the pullets grow, it will eat just about anything that catches its interest. It will also need a dirt run, preferably a sunny spot, to take dirt baths on. If pets are what you want, you would settle well with bantams. Bantams are chicken breeds that are about one fourth of the size of a regular chicken. It is very much like having toy dog breeds. Example of the bantam breeds that are good for pets are the Barred Plymouth Rocks and the Rhode Island Reds as they are mild tempered.