The fully developed embryo breaks open the shell when it is time.
Since the beak and the claws are not fully developed, birds have an “egg tooth.”
In birds, the process of breaking open the eggshell is referred to as pipping.
When a chick becomes too large to absorb oxygen through the pores of its eggshell, it uses its egg tooth to peck a hole in the air sac located at the flat end of the egg. This sac provides a few hours’ worth of air, during which the chick breaks through the eggshell to the outside. The egg tooth falls off several days after hatching
Bald Eagles and Ospreys never fly together. The male Osprey is defending his nest from the eagle.
Since Eagles share very much the same lifestyle and habitat as the Osprey, these two are often in conflict. They will raid each other’s nest’s, taking the babies of the other. The Eagle often attacks Ospreys in mid-flight to steal his hard-earned fish, so Ospreys take advantage of every opportunity to harass Eagles in return. Neither wants to share prime fishing areas with the other.