They are still huddled to the center under the lamp. So probably still a little cold. Also, when they are that young, to ensure they are feeding, I dump some food on the floor near/around the food dish. Its a bit messy, but they will learn to scratch and peck at it. Better that they eat when they are that young, and not worry about waste. If there is any draft or possibility of one, it might be worth covering the open sides a little(cardboard or light blanket). Make sure there is some air flow, but it could also help retain some heat in the tub for them, which I am pretty sure they still need.
Did you get a thermometer in there yet? Any thermometer will help you get an idea of how close you are to ideal temps.