SRD:Psionic Scent

You gain an enhanced sense of smell, equivalent to the scent ability of some monsters. This ability allows you to detect approaching enemies, sniff out hidden foes, and track by sense of smell. With the scent ability, you can identify familiar odors just as humanoids do familiar sights.

You can detect opponents within 30 feet by sense of smell. If the opponent is upwind, the range increases to 60 feet; if downwind, it drops to 15 feet. Strong scents, such as smoke or rotting garbage, can be detected at twice the ranges noted above. Overpowering scents, such as skunk musk or troglodyte stench, can be detected at triple normal range.

When you detect a scent, the exact location of the source is not revealed—only its presence somewhere within range. You can take a move action to note the direction of the scent. Whenever you come within 5 feet of the source, you pinpoint the source’s location.

If you have the Track feat, you can follow tracks by smell, making a Wisdom (or Survival) check to find or follow a track. The typical DC for a fresh trail is 10 (no matter what kind of surface holds the scent). This DC increases or decreases depending on how strong the quarry’s odor is, the number of creatures, and the age of the trail. For each hour that the trail is cold, the DC increases by 2. The ability otherwise follows the rules for the Track feat. If you are tracking with psionic scent, you ignore the effects of surface conditions and poor visibility.