ride herd on

ride herd on sb/sth (watch closely and control sb)
— неусыпно / неустанно следить за; контролировать; держать в строгих рамках; держать в подобающих рамках; держать в узде

Example 1: She has a reputation for riding herd on the workers.

Example 2: I'm tired of having to ride herd on her kids all the time.

Example 3: Given that those 40 inspectors were expected to ride herd on more than 2,000 bars and restaurants, it's no surprise they needed all the help they could get.

Example 4: She ran a tight ship, riding herd on restless customers waiting in line, discouraging patrons from lingering after meals and insisting on payment in cash only.

---------------
Originally, to patrol on horseback around a herd of animals to see that none of them wanders away (охранять стадо и т. п., объезжая его верхом).

see also
[run a tight ship]
[keep a tight rein on sb]