crawl back into (someone's) shell

Translations
уйти в (себя)
After the argument, he decided to crawl back into his shell and didn't speak to anyone.
После ссоры он решил уйти в себя и ни с кем не разговаривал.
Definitions
To withdraw from social interaction or become less outgoing, often due to shyness, embarrassment, or a negative experience. The phrase likens a person to a turtle retreating into its shell for protection.
Words
shell

noun
раковина
crawl

verb
ползти
crawl back

verb
ползти обратно
back

adverb
назад