go on the prowl
1. To start to actively and perhaps aggressively seek a sexual partner, especially during a certain situation or in a certain setting. Now that I'm single, I plan to go on the prowl at the bar tonight.
2. To start to actively search for someone or something. Usually followed by "for" and the thing being sought. I went on the prowl for a new television at a good price but found nothing.
be/go on the ˈprowl
1 (of animals) move around quietly while hunting for food: Our cats go on the prowl at night, and then they sleep here all day.
2 (of people) be moving around quietly because you are trying to catch somebody or intending to commit a crime: Look out for burglars on the prowl. If you see anything suspicious, call the police immediately.