Eggs should not be eaten after 3 months in the refrigerator. The usual shelf life of eggs in the refrigerator is 40 days. Eggs that have been in the refrigerator for 3 months have deteriorated, or even spoiled, and should not be eaten. Eggs are more likely to spoil in the summer when temperatures are high. There are some tips to quickly distinguish whether eggs have deteriorated, such as shaking eggs, no sound is fresh eggs, there is a muddy water sound is bad eggs, may be spoiled. When eggs are placed in water, those that sink to the bottom are fresh eggs and those that float to the surface are bad eggs. If the egg is opened without shaking the egg in advance, if the yolk coalesces in a round shape, it is a fresh egg, while a bad egg is a scattered yolk. It is important to note that if an egg is expired, do not continue to eat it. A large number of bacteria have multiplied in expired eggs, and eating these bacteria directly into the abdomen can produce strong gastrointestinal reactions such as nausea, vomiting, diarrhea, abdominal pain and other food poisoning phenomena.