I see people posting photographs of daily candlings - so assuming it's ok to check once a day? From a mamma duck - she doesn't mind or complain. I have been checking at night by flashlight. After seeing a huge amount of movement/swishing in one I'm addicted - it's so fascinating!! I'd like to check that they are all fertile but trust she will do her thing and I just steal the ones on the edge underneath her and put them back. we're at 2 weeks now. I couldn't believe all the whooshing??? Heartbeat? The others weren't near as "busy" but vein-y and could see the embryo. **I roll them, ever so slowly, and wait if I don't see the embryo - please tell me that hasn't hurt them!!