Translation guide
The process of a young animal emerging from an egg. In Japanese, different verbs are used depending on the animal and context, and there are also specific terms for artificial hatching.
To describe an egg hatching naturally, or an animal hatching from an egg.
The egg hatched.
The chick hatched from the egg.
A common verb meaning 'to hatch' or 'to be born from an egg'. Often used in everyday speech for birds and insects. Intransitive.
The swallow chicks hatched.
Kanji form of かえる, but rarely used. Usually written in kana.
The egg hatched.
To describe hatching eggs artificially, as in poultry farming or conservation.
To use more specific or traditional verbs for certain animals hatching.
Used specifically for insects emerging from pupae (eclosion), like butterflies or cicadas. Not for egg hatching.
The cicada emerged (from its nymphal skin).
Means 'to be born', sometimes used poetically for hatching, especially in documentaries or children's stories.
Baby sea turtles were born on the sandy beach.
To refer to the act or process of hatching as a noun.
Both mean 'to hatch', but 孵化する is more formal and scientific, while かえる is common in everyday conversation. 孵化する can be transitive (卵を孵化する) or intransitive (卵が孵化する), whereas かえる is only intransitive.
羽化 (うか) specifically refers to insects emerging from their pupal stage, not hatching from an egg. Using it for egg hatching would be incorrect.
We hatched chicken eggs in an incubator.
The incubation period is about 21 days.