debris in air intake for engine failure on 2010 Toyota Prius

should this be covered by warranty if within 36 months and three years?

,If the factory air filter and its attachments were in place, how did, and what kind of, debris got into the intake?? Mice eat their way through the air filter?
replaced with a Fram air filter then no debris that i could see but hybrid system failure. system must be very delicate...factory manual says not to run car without air filter as harmful to engine but car should run with fram air filter. dealer reset codes.