Bevendre

Changelings are slightly psychic, and when hungry will sense an aura of love around individuals.  The love they sense doesn’t have to be directed towards them.  It can be general love radiating out of a pony like water from a sprinkler, or directed love being pointed to a single individual.  
A changeling can feed off of general love, but directed is far more filling and nourishing as it’s more whole and, well, direct.  To feed off of that though, a changeling must replace the one the love is being directed towards.