Yesterday chirping inside cockatiel egg - today no is this normal?

No, it's not normal for the chirping inside a cockatiel egg to suddenly stop. When an egg is fertile and developing normally, the embryo inside will start making small noises, such as chirping or peeping, as it grows and develops. Hearing these noises is a good indication that the egg is viable and that the embryo is alive.

If you heard chirping inside the egg yesterday and it has suddenly stopped today, it's possible that something has happened to the embryo and it has died. This can happen for a variety of reasons, including:

* Incubation issues: Cockatiel eggs need to be incubated at a consistent temperature and humidity in order to develop properly. If the temperature or humidity is too high or too low, it can cause the embryo to die.

* Nutritional deficiencies: The hen who laid the egg may not have been getting enough nutrients, which can lead to the embryo developing problems or dying.

* Genetic defects: Some cockatiel eggs may have genetic defects that make them inviable.

If you're concerned about the egg, you can take it to an avian veterinarian for examination. The veterinarian can use an ultrasound machine to check the egg for signs of life and can also determine if there are any problems with the embryo.