The term 'certain rodent' can refer to three different animals: the RAT, the GERBIL, and the sewer RAT. The RAT is a small mammal with a long tail, typically found in cities and other populated areas. The GERBIL is a small, burrowing rodent native to the deserts of North Africa and Asia. The sewer RAT is a species of RAT that lives in sewers and other underground habitats. All three animals are considered to be rodents, and they all have certain characteristics in common, such as their sharp teeth and long tails.