We check eggs fertilized after 6 days and 18 days of incubation. I prefer to make it towards 17 days not to take the risk to put in the bin some fertilized eggs. It is easy at this stage to see the difference (see photos this photos below). 1) To make a candler from a lamp dynamo you need: - A dynamo lamp (approximately 5€) - Adhesive tape for electricity - A cardboard tube (coming from an absorbing paper roller) - A cutter or scissors. 3) Use the adhesive tape to maintain the cardboard tube 2) Cut the cardboard tube to fit it to the extreme side of the lamp It consists in steering a beam of light concentrated on the egg to see inside by transparency. It exists candler ready to buy but it is easy to make one by using one empty metal food box in which we will place a lamp on a side and we shall realize a small hole of diameter equal to a 1-cents coin of euro on the other one or by using lamps dynamo in led which have for advantage of not heat the egg. 4) Put the egg on the tube when the lamp is on (it must be dark around you) None fertilized egg Egg fertilized (we see the pocket of air) An egg candler GeneralitiesRacesTo understand chickensFrench law and the cockBooksA good startRingsAnatomyFoodReproductionFirst pageHen houseHealthMake itthe egg The hen and youlinks hen house generalities races a good start rings anatomy to understand chickens golden book The hen and you health reproduction law and cock food What have we done to chickens? make it Contacts first page Mention Légales Français / Anglais French / English the egg an Orpingtonmania website Golden bookLinksPoultry will have no secret for you, welcome.