Catchy
Catchy , adjective
1.
Apt or tending to catch the fancy or attention; catching; taking; as, catchy music.
2.
Tending to catch or insnare; entangling; -- usually used fig.; as, a catchy question.
3.
Consisting of, or occurring in, disconnected parts or snatches; changeable; as, a catchy wind.
It [the fox's scent] is... flighty or catchy, if variable.