A641

Yes and no. Yes they are aware that an attempt of some sort has been made. No they are not aware that it was a scrying attempt.
Quote Originally Posted by Succeeding on a Saving Throw
A creature that successfully saves against a spell that has no obvious physical effects feels a hostile force or a tingle, but cannot deduce the exact nature of the attack. Likewise, if a creature’s saving throw succeeds against a targeted spell you sense that the spell has failed. You do not sense when creatures succeed on saves against effect and area spells.