Embryo
Laying an egg.
Young turkeys of any gender are called poults, females are Hens and males are called Toms.
Praying Mantis are start out as an egg mass called ootheca.
Immature snakes are referred to hatchlings after emergence from their egg and are then called juveniles.
Egg, tadpole, young, frog
Worker
No. Echidna are egg laying mammals. However, they do suckle their young with milk. Egg laying mammals are called monotremes.
A Baby Praying Mantis is Called a Nymph which is between the egg and adult stage.
It's called laying an egg. When the gosling emerges from the egg, it's called hatching.
An antling is a young ant that has hatched from an egg. An ant's body has three sections, the head, thorax, and gaster.
It is called an ootheca (its the same for all insects)
This is called embryology or developmental Biology.