足元あしもとから鳥とりが立たつ

Idiom

1for something unexpected to happen (to someone or something one is close to) Translated by Jiyomi
2(deciding to do something) abruptly ; at the turn of a dime

expressions (phrases, clauses, etc.) · Godan verb with 'tsu' ending

JMdict entry 2834644. Source and licence.