That's Odd Feat 1
Source Pathfinder Advanced Player's Guide
When you enter a new location, such as a room or corridor, you immediately notice one thing out of the ordinary. The GM determines what it is, or whether there's nothing reasonable to pick up, skipping obvious clues that can be easily noticed without a check or specifically looking for them. You learn only that an area or object is suspicious, but not why it's suspicious.
For example, if you entered a study with a large bloodstain on the ground, the bloodstain is so obviously suspicious it's evident to you already, so the GM might note that there's something suspicious about the desk drawer instead. You would then need to investigate the drawer further to find out what specifically is out of the ordinary. That's Odd doesn't reveal whether creatures are suspicious.
You don't typically get any benefit when you leave and come back to a place, though if a major change has happened there and time has passed, the GM might determine that you do.
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
InvestigatorThis indicates abilities from the investigator class.