They could be egg bound, and that is serious. If you have a vet, that would be best. In the meantime and in any case, get them into a tub with lukewarm water and let them float around for an hour or so. Are they getting calcium supplements? Like oyster shell, layer feed? I would start them on calcium gluconate 23% (available at many feed stores or online), 1 teaspoon per half cup of water added to their food.