To determine if eggs are fertilized, a simple method known as candling can be employed. Hold the egg in a dark room towards a bright light source, such as a flashlight. If the egg appears translucent with a distinct dark spot (the embryo), it’s likely fertilized. Another method involves placing the egg in a glass of lukewarm water. A fertilized egg will sink to the bottom, while an unfertilized one will float. Both techniques allow you to assess the egg’s internal contents, aiding in distinguishing fertilized eggs from unfertilized ones.