I believe the final episode of season one of Westworld gives some indication that Felix might be a host:
- Maeve's escape was not her own idea, but a storyline given to her by someone else (presumably Robert Ford). Therefore, anything that happens to Maeve has been engineered to some degree (also presumably by Ford).
- Felix and Sylvester are really dumb, to the point that it comes across as just bad writing in earlier episodes. If one or both of them are programmed to help Maeve that would go some way to explaining what would otherwise be terrible lapses of judgement.
- We know of at least one other staff member who is a host (Bernard), so this wouldn't be unprecedented
- Felix also shows some aptitude for programming (he brought the animatronic bird back to life), a trait that he shares with Bernard
- We know that hosts can be programmed to see other hosts as human. This explains why Maeve is confident enough to tell Felix that he isn't "one of us". And since Maeve doesn't realise she's still on a loop, she may also not realise that she can't distinguish between humans and hosts.
Is there any other evidence that Felix is (or is not) a host?