Both started this at the same time? How long have they been this way. Do they fluff up, squawk or growl at you when you try to move them? Do you know when they last laid?
Droppings normal? Feel crops to see if they are empty, full, soft & squishy, hard, etc. Any wheezing, sneezing, coughing or discharge from eyes, nares or beak?
Quick thoughts, maybe broody, meaning they want to sit and hatch eggs. When that happens they will often refuse to leave the nest except for a couple of times a day to poop, eat and drink, and not for long. If this is the case, you can break them of broodiness. If they are sick, then knowing the answers to the other questions, may help to narrow it down.