The first incubator we built was 2 ft x 2 ft x 4 ft high, and uses a small computer fan to circulate air from the bottom and up a duct at the back that discharges air onto each of up to 5 shelf levels of adjustable height.  We originally designed this incubator to accommodate the large number of colubrid eggs that we were producing years ago. It works well, but the danger is that if the fan fails, you get a big temperature gradient from top to bottom. This very problem caused the demise of half a clutch of woma eggs one season.

For this reason, we have stopped using tall incubators - we use ours as a baby rack now. The easiest way to construct an incubator is to use a plastic cooler of appropriate size (you can also construct a simple box from a number of different wood or plastic building materials). We use a section of 11-inch wide heat tape on the bottom of the cooler (inside the cooler) as the heat source, and place the incubation box on a wire rack elevated a couple inches off the bottom above the heat tape. The electric cord for the heat tape and the sensor for the thermostat are run through the drain plug opening of the cooler. We tape the thermostat sensor onto the wire rack right next to the incubation box.

Alternatively, the heat tape can be attached to the inside of the cooler lid, the perlite/vermiculite mix placed directly into the cooler, and the thermostat sensor placed directly in the perlite/vermiculite mix right next to the eggs. With this arrangement, the cooler also serves as the incubation box, which lets you use all of the space in the cooler. This alternative will allow the incubation of two clutches of woma eggs in one large cooler/incubator, but doesn't work if the eggs are stuck to the nest box forcing you to put the whole nest box into the incubator – so have a backup plan! Be certain that your nest box is big enough to facilitate the incubation strategy detailed on our Egg Incubation and Hatching Page, but also be sure to have an incubator ready to go that will accommodate the entire nest box if necessary.