scent bag
/ˈsɛnt baɡ/noun
1A sac or pouch possessed by some animals, containing an odorous substance which is typically released during courtship or in self-defence; a scent gland.
2A sachet or pouch for holding aromatic substances, intended to be placed among articles of clothing or carried about the person.
3(A) A bag containing paper pieces used to create a trail for the game of 'Hare and Hounds' (now rare ). (b) Chiefly in trail or drag hunting: a bag containing a strong-smelling substance drawn over ground to make an artificial scent trail for hounds to follow.
Origin
Late 17th century; earliest use found in Robert Plot (bap. 1640, d. 1696), naturalist and antiquary. From scent + bag.