Male dogs use pheromones in urine to mark their territory, and pheromones are natural aphrodisiacs. Given these facts, what do male dogs use in urine to mark their territory among the following options:
- Natural aphrodisiacs
 - competing for resources
 - Tails
 - Urine  cleaner
 - Something coming from a gland
 - Chemical energy
 - an area swollen with pus
 - Chew toys


 

 Natural aphrodisiacs        