Scent Trail

Transmutation
Level: Druid * 2, Hunter * 2
Components: V, S, M (a queen ant)
Casting Time: 1 Standard Action
Range: close (25 ft. + 5 ft./2 levels)
Target: one creature/level, no two of which can be more than 30 ft. apart
Duration: 1 hour/level
Saving Throw: Fortitude negates (harmless)
Spell Resistance: yes (harmless)
  You, or a willing creature you touch, lay down a trail of scents that only the creatures you designate at the time of can detect. These creatures find it very easy to follow this trail.
  They gain a +20 Competence Bonus on any Survival checks made for the purpose of tracking the creature laying this trail.
  Subject creatures with the Scent special ability gain a +10 Competence Bonus on Wisdom or Survival checks to follow the trail.
  In addition, you can leave Scent messages along the trail.
  Each word or emotion in this message requires spending a Move Action in the same spot. Subject creatures seeking to understand this message must make another DC 20 Survival check, with a -1 penalty for every word or emotion in the message, in order to understand it. Creatures cannot benefit from this smell if they cannot use, or do not have, a sense of smell. Creatures can use this spell to backtrack through a dungeon, maze, or similar areas even if the creature laying down the trail crossed over the spot multiple times.