"Extremely Negatively polarized" Scientist

[Stranger]

I can't understand how a being can survive and thrive on fear, like it's a food. Do they eat or ingest our fear?

Exactly so. Remember they are not feeding physical (i.e. what Ra calls chemical) bodies - they don't have those.

e.g.:

What the fifth-density entities, which you may call, as this instrument has jokingly done, “space pirates,” have in mind is simply to have a continuing harvest of food, that food being fear. You may see [the creation of an atmosphere of fear] in your governmental systems in your present culture.