When I first built my incubator after I got temps regulated I couldn't wait a few days to get the fresh barnyard mix I planned on hatching, so I pulled four eggs from fridge I had gotten from friend. They had been in my fridge probably 10-12 days. Not sure how old were when givin to me. But after 11 days I see great movement and even kicking in one! The others all look clear. My son was amazed