smell blood

Translations
чуять слабость
The competitors smelled blood when they saw the company's financial troubles.
Конкуренты почуяли слабость, когда увидели финансовые проблемы компании.
Definitions
To sense or perceive a situation that indicates danger, vulnerability, or an opportunity, often used in a figurative sense to describe someone who is eager to take advantage of another's weakness.