This is our first day out of the incubator and the temperature of our heat lamp is reading a little lower than I'd like but we also have it set across from the heat lamp and a little bit pushed back because in other places the ducklings were trying to eat the thermometer. Right now they're not exactly under the heat lamp there a little off side so I would assume they're fine. But I feel the need to cover up most of the top to keep them warm. Is this enough ventilation? I've only left enough opening to not burn the sheets down that are surrounding the top. They're in a large storage tupperware.