The focus of the series is on the adventures of the two rats, including guarding the cheese, interacting with other stowaways and various ill-fated encounters with the crew.

Ratz mainly focuses on a duo of the eponymous rats, Rapido and Razmo, whose contrasting personalities often have them butt heads with each other.

The series' titular duo are composed of two pitch-black rats, Rapido and Razmo, wearing helmets (with goggles attached) and outfits akin to a modern-day pilot (in red and blue, respectively), with elongated ears, lavender eyemask patterns and long snouts.

Ratboards are also used to reach otherwise inaccessible places, provide speedy rescues, move things by tether or simply to impress guests.

Humorously enough, the crew's diet consists mostly of cheese (their cargo), which Svetlana hates and Benny is allergic to (although said allergies are not seen or discussed within the show).

While being targeted at young children in France, the series has gained a small cult following of older ages in Canada, due to its late-night timeslot.