Meaning of the word "have kittens" in English

What does "have kittens" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

have kittens

US /hæv ˈkɪt.ənz/
UK /hæv ˈkɪt.ənz/

Idiom

to be extremely anxious, upset, or angry about something

Example:
My mother will have kittens when she sees this mess.
Don't tell him yet, or he'll have kittens.