Crossword Clue:

to follow by scent

Answer	Crossword Clue
TRAIL	Follow the scent
SMELLOUT	Detect by scent
NOSE	Detect by scent.

NOSED	Detected by scent.
ABIDE	Follow, with "by"
TRACE	Follow by footprints.
TRACE	Follow step by step.
ABIDE	Follow the rules with by
NEAPS	They follow springs by about seven days
NEAPS	They follow springs by about a week