Patrat have often imagined themselves as perfect sentries, and were once known for standing on castle walls to keep watch in captivity, a habit they continue onto the walls of houses in more modern times. This likely harkens back to their behavior in the wild, where they constantly watch over their nests for fear of being robbed, even when they have no eggs or young to protect from predators. Few humans wanted these pokemon in that role, but the ability to keep food in their cheek pouches and go for days without eating, which they use in the wild on guard duty, has not gone unappreciated by Man.
Although well-worn paths often connected cities even in ancient times, any individual who wished to travel elsewhere would still at some point need to pass through tall grass. Even now, roads are often not completely clear of wild pokemon, and some settlements can claim no true roads at all. For a pokemon trainer, this is simply part of the challenge of their adventure, but for those who never put the time and money into raising powerful pokemon, even moving to the next town over can be a task fraught with danger – a danger which can be dramatically reduced by hiring Patrat, who require no food over the course of the journey and whose keen senses can guide the way to safety.
The invention of the Repel has caused some to question the continued viability of Patrat as guides. However, the current formulas, but require powerful pokemon to work, and Patrat come far cheaper for non-trainers than the currently available Repel and pokemon rental combinations. And should they all return to the wild, few would lack for Patrat sightings, for they remain extremely common wherever in Unova tall grass grows.