Homemade chicken incubators can be used to hatch eggs as a science experiment, or to hatch eggs to increase the number of chickens you raise for the table. You can make a homemade chicken incubator using a box and a heat source, or create a more elaborate structure. Your incubator must allow you to control the temperature and humidity inside the incubator, and access the eggs for turning.
The Incubator Box
What your incubator is made from really doesn't matter so long as there are openings at the top and bottom that allow air to flow in and out of the box. You only need a few small ventilation holes because you need a warm humid atmosphere inside the incubator. You'll also need openings to allow for your other equipment, such as your heater. You will need something to hold the eggs: recycled egg cartons, or commercial egg trays. The incubator needs to be large enough to accommodate the number of eggs you want to hatch at one time and the equipment you will need.
The optimum range for hatching chicken eggs is between 97 and 103 degrees Fahrenheit. Twenty-five watt incandescent light bulbs are common choices as a heat source. You can purchase a heating element manufactured specifically for chicken incubators, or one used for keeping pet reptiles. Whatever source of heating you choose, you need a thermostat to monitor the temperature. Depending on your skill with electrical equipment, you may be able to construct your own thermostat, or you may wish to purchase a commercial thermostat.
A hygrometer measures the amount of humidity in the air. The air inside your chicken incubator should have between 60 percent and 75 percent humidity. You can purchase single devices that work as both thermostats and hygrometers. To get the needed humidity in your incubator, place a pan of water in the bottom; the heat from the incubator will cause the water to evaporate into the air, creating humidity. As you check your incubator throughout the day, you can change the amount of water in the pan to adjust the humidity level.
Turning the Eggs
Wash your hands with soap and water and dry them completely before handling the eggs. Do not use alcohol-based hand sanitizers. Turn your eggs four times a day, turning 90 degrees clockwise each time with the large, rounded end of the egg remaining upright. To track turning, use a nontoxic marker or pencil to mark the egg; do not use permanent markers. Turning equalizes stress on the growing chicken so that it will develop properly. Your incubator should allow you to access the eggs easily for turning while minimizing the loss of heat and humidity.
When your eggs begin to hatch, check your incubator no less frequently than every eight hours. If you see a chick emerging, leave it to its own devices. Healthy chickens will emerge on their own; if you help unhealthy chickens hatch, you are only lengthening the amount of time it takes for them to perish. Once your chick has hatched, is dry and peeping, move it from the incubator into a brooder. The percentage of eggs that hatch will vary. Any chicken eggs that have not hatched after 23 days should be discarded. Your incubator should be cleaned before you begin with a new set of eggs.