Sounds like maybe they are cold. I had to turn back on the lamp for my 5 week old bantam Polish and buff Brahma chicks to keep them warm enough with the temps dropping.
just went down to my coop, just after the sun went down, to check on everyone -- and the two newcomer chicks (7 week old Delaware & slightly younger australorp) were both totally distressed, making loud sharp insistent peeping noises and taking turns trying to duck under each other's breast, the way they would as a chick with a hen -- they've got lots of food and water, so not sure why they seemed so upset? i at least got them both into the henhouse, which should be a little warmer, and the marans chicks (same age but much bossier) stayed out in the run... but goodness, so upsetting to not know what might be freaking them out so!
poor little girls...