Where a snake or viper lurks, one cannot help being on guard.
Tips
history
虺 is not used independently in modern Chinese. As huǐ it means a small venomous snake (the compound 蛇虺); a second reading huī appears only in the 诗经 line about a weary horse. It joins the phonetic 兀 with the insect/reptile radical 虫.
register
Archaic and literary only; encountered in classical texts and etymology notes, not in modern speech.