I used one of the red plug spots to put a thermometer in. There is a thread with tricks to hatching in the LG and it was very helpful. I had a hard time keeping the temperature steady as it tended to drift. The room it is in needs to have a steady temperature as well as the thing dose t have enough mass to hold heat steady. I had a 30 percent hatchI have no idea what the purpose of those red plugs are...maybe decorations that block oxygen