As another example, rats leave a trail of urine wherever they go.
Just imagine one just taking a leisurely stroll through a food storage area... maybe over some dry storage boxes....

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Urine mark, or scent mark: The rat deposits tiny droplets of urine on the surfaces and objects he walks on. Considered an advertisement of the rat's presence and a sex attractant. Urine may be deposited by: (1) anogenital drag: rubbing hindquarters over top of object, leaving a trail of urine as the rat steps over it; or (2) leg-lift: lifting hind leg nearest the object and urinating on one corner while standing, or walking beside the object with one hind foot on top of it, leaving a trail of urine along the entire length of the object (Brown 1975). Rats may urine mark each other using the (3) crawl-over. </div></div>