ANATOMY

Detailed explanation-1: -The only ‘tooth’ seen in birds is the ‘egg tooth’. This is a hard, sharp protrusion on the rostrodorsal side of the upper beak in birds that have just hatched. The egg tooth helps the chick to break through the eggshell.

Detailed explanation-2: -On the 21st day, the chick begins to break out of the shell. Using its egg tooth, it first pecks a hole through the shell. Then it pecks a circle around the end of the egg. The chick twists its neck and pushes with its feet and breaks the shell open.

Detailed explanation-3: -Hatching: the chick breaks free of the shell.

Detailed explanation-4: -A hatching chick has to work hard for hours or even days to break through the shell. The chicks of most birds have a tiny bump near the tip of the beak, called the egg tooth, to help them. The egg tooth usually falls off or wears away during the first few weeks of life.

Detailed explanation-5: -In the chicken, the chick punctures the air cell about thirty hours before hatching, makes its rst pip of the eggshell at twelve hours before hatching, and starts to rotate within the shell just fty minutes before it emerges.