prey on

prey on (third-person singular simple present preys on, present participle preying on, simple past and past participle preyed on)

1. (transitive) To eat (as prey).

   Owls prey on small mammals, such as mice.

2. (transitive, figuratively) To exploit or victimize.
   • 2013 January 22, Phil McNulty, “Aston Villa 2-1 Bradford (3-4)”, in BBC‎:

     Bradford had preyed on Villa's inability to defend set pieces, corners in particular, in their first-leg win and took advantage of the weakness again as Hanson equalised to restore their two-goal aggregate lead.

3. (transitive, figuratively) To weigh heavily upon (a person's mind).

• Poyner, pyrone