I set mine in front of the window thinking the warmth would be great and it wouldnt be too hot as an air vent is right there..Well, they have all shriveled..not went hard to pupate, but just shriveled and died.. I know before I cooked em. i set em on a heat linear bulb and whala, fried fruit fly eggs! So yea, they must be pretty sensitive. I have my other culture under my fish tank where the back is ope and it gets light but no directly.